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David E Wildt - One of the best experts on this subject based on the ideXlab platform.

  • The phenomenon and significance of Teratospermia in felids.
    Journal of reproduction and fertility, 2020
    Co-Authors: Budhan S Pukazhenthi, David E Wildt, Jogayle Howard
    Abstract:

    The common domestic cat is an important research model for endangered felids, as well as for studying genetic dysfunctions, infectious diseases and infertility in humans. Especially significant is the trait of Teratospermia (ejaculation of < 40% morphologically normal spermatozoa) that commonly occurs in about 70% of the felid species or subspecies studied to date. Teratospermia, discovered more than two decades ago in the cheetah, is important: (i) for understanding the significance of sperm form and function; and (ii) because this condition is common in human males. It is apparent from IVF that deformed spermatozoa from teratospermic felids do not fertilize oocytes. However, the inability of spermatozoa from teratospermic males to bind, penetrate and decondense in the cytoplasm of the oocyte is not limited to malformed cells alone. Normal shaped spermatozoa from teratospermic males have reduced functional capacity. IVF results have consistently revealed a direct correlation between Teratospermia and compromised sperm function across felid species and populations. The most significant differences between normospermic (> 60% normal spermatozoa per ejaculate) and teratospermic felids include: (i) the time required for sperm capacitation and the acrosome reaction to occur in vitro; (ii) culture media requirements for capacitation in vitro; (iii) phosphorylation patterns of tyrosine residues on sperm membrane proteins during capacitation; (iv) susceptibility to chilling-induced sperm membrane damage; (v) sensitivity to osmotic stress; (vi) stability of sperm DNA; (vii) sperm protamine composition; and (viii) fertilizing ability after intracytoplasmic sperm injection. In conclusion, (i) the felids (including wild species) are valuable for studying the functional significance of both pleiomorphic and normally formed spermatozoa from teratospermic donors, and (ii) the impact of Teratospermia is expressed at both macrocellular and subcellular levels.

  • oxidative phosphorylation is essential for felid sperm function but is substantially lower in cheetah acinonyx jubatus compared to domestic cat felis catus ejaculate
    Biology of Reproduction, 2011
    Co-Authors: David E Wildt, Linda M. Penfold, Kimberly A Terrell, Nicola M Anthony, Barry D Bavister, S P Leibo, Laurie Marker, Adrienne E Crosier
    Abstract:

    Compared with the normospermic domestic cat, sperm metabolic function is compromised in the teratospermic cat and cheetah, but the pathway(s) involved in this deficiency are unknown. Glycolysis is essential for sperm motility, yet it appears to function normally in spermatozoa of either species regardless of structural morphology. We conducted a comparative study to further understand the mechanisms of energy production in felid spermatozoa, with the hypothesis that oxidative phosphorylation is required for normal sperm function and is impaired in teratospermic ejaculates. Electroejaculates from both species were stained with MitoTracker to quantify mitochondrial membrane potential (MMP) or were incubated to assess changes in sperm function (motility, acrosomal integrity, and lactate production) after mitochondrial inhibition with myxothiazol. Sperm midpiece dimensions also were quantified. Sperm mitochondrial fluorescence (directly proportional to MMP) was ;95% lower in the cheetah compared with the normospermic and teratospermic cat, despite the cheetah having a 10% longer midpiece. In both species, MMP was increased 5-fold in spermatozoa with retained cytoplasm compared with structurally normal cells. Inhibition of oxidative phosphorylation impaired sperm function in both species, but a 100-fold higher inhibitor concentration was required in the cat compared with the cheetah. Collectively, findings revealed that oxidative phosphorylation was required for sperm function in the domestic cat and cheetah. This pathway of energy production appeared markedly less active in the cheetah, indicating a species-specific vulnerability to mitochondrial dysfunction. The unexpected, cross-species linkage between retained cytoplasmic droplets and elevated MMP may reflect increased concentrations of metabolic enzymes or substrates in these structures. cat, gamete biology, lipid, mitochondria, myxothiazol, spermatozoa, sperm metabolism, sperm motility and transport, Teratospermia, teratozoospermia

  • the impact and potential etiology of Teratospermia in the domestic cat and its wild relatives
    Theriogenology, 2006
    Co-Authors: Budhan S Pukazhenthi, Jogayle Howard, Katrin Neubauer, Katarina Jewgenow, David E Wildt
    Abstract:

    Teratospermia (production of >60% morphologically abnormal sperm/ejaculate) is relatively common among various species in the family Felidae, which is comprised of 37 species. Over two decades of research in this area have produced a significant understanding of the phenotypic expression, its impacts on sperm function and etiology. There is good evidence suggesting that a reduction in genetic diversity contributes to this phenomenon. Results to date demonstrate that spermatozoa from teratospermic donors are compromised in the ability to undergo capacitation and the acrosome reaction, penetrate the zona-pellucida, fertilize conspecific oocytes and survive cryopreservation. Recent studies also reveal abnormalities in chromatin integrity in sperm from teratospermic donors, which, interestingly, fails to impact fertilization or embryo development after intracytoplasmic sperm injection. Through planned inbreeding studies, we now have established that teratospermic cats also produce more spermatozoa by virtue of more sperm producing tissue, more germ cells per Sertoli cell and reduced germ cell loss during spermatogenesis. Overall, it now is clear that gain in sperm quantity is achieved at the expense of sperm quality, suggesting an extensive disruption of normal testicular function in teratospermic donors. Preliminary studies on testicular gene expression in teratospermic cats have also revealed abnormal expression patterns. These findings have markedly increased our understanding of testis biology in the teratospermic donor and reaffirm the value of cats, including wild species, as models for studying novel regulatory mechanisms controlling spermatogenesis and spermiogenesis.

  • Normospermic versus teratospermic domestic cat sperm chromatin integrity evaluated by flow cytometry and intracytoplasmic sperm injection.
    Biology of Reproduction, 2003
    Co-Authors: Linda M. Penfold, Lorna K. Jost, Donald P. Evenson, David E Wildt
    Abstract:

    Teratospermia (>60% of morphologically abnormal spermatozoa) is well documented in felids. Even morphologically normal spermatozoa from teratospermic ejaculates have reduced ability to undergo tyrosine phosphorylation, acrosome react, and bind and penetrate oocytes compared with normospermic ( 0.05) proportions of oocytes fertilized after ICSI using spermatozoa from normo- and teratospermic cats. Results reveal that Teratospermia in the cat is expressed at the nuclear level as increased sperm chromatin heterogeneity, but ICSI showed that this does not apparently affect fertilization rates if the zona pellucida and oolemma can be bypassed.

  • the phenomenon and significance of Teratospermia in felids
    Journal of reproduction and fertility, 2001
    Co-Authors: Budhan S Pukazhenthi, David E Wildt, Jogayle Howard
    Abstract:

    : The common domestic cat is an important research model for endangered felids, as well as for studying genetic dysfunctions, infectious diseases and infertility in humans. Especially significant is the trait of Teratospermia (ejaculation of 60% normal spermatozoa per ejaculate) and teratospermic felids include: (i) the time required for sperm capacitation and the acrosome reaction to occur in vitro; (ii) culture media requirements for capacitation in vitro; (iii) phosphorylation patterns of tyrosine residues on sperm membrane proteins during capacitation; (iv) susceptibility to chilling-induced sperm membrane damage; (v) sensitivity to osmotic stress; (vi) stability of sperm DNA; (vii) sperm protamine composition; and (viii) fertilizing ability after intracytoplasmic sperm injection. In conclusion, (i) the felids (including wild species) are valuable for studying the functional significance of both pleiomorphic and normally formed spermatozoa from teratospermic donors, and (ii) the impact of Teratospermia is expressed at both macrocellular and subcellular levels.

Jogayle Howard - One of the best experts on this subject based on the ideXlab platform.

  • The phenomenon and significance of Teratospermia in felids.
    Journal of reproduction and fertility, 2020
    Co-Authors: Budhan S Pukazhenthi, David E Wildt, Jogayle Howard
    Abstract:

    The common domestic cat is an important research model for endangered felids, as well as for studying genetic dysfunctions, infectious diseases and infertility in humans. Especially significant is the trait of Teratospermia (ejaculation of < 40% morphologically normal spermatozoa) that commonly occurs in about 70% of the felid species or subspecies studied to date. Teratospermia, discovered more than two decades ago in the cheetah, is important: (i) for understanding the significance of sperm form and function; and (ii) because this condition is common in human males. It is apparent from IVF that deformed spermatozoa from teratospermic felids do not fertilize oocytes. However, the inability of spermatozoa from teratospermic males to bind, penetrate and decondense in the cytoplasm of the oocyte is not limited to malformed cells alone. Normal shaped spermatozoa from teratospermic males have reduced functional capacity. IVF results have consistently revealed a direct correlation between Teratospermia and compromised sperm function across felid species and populations. The most significant differences between normospermic (> 60% normal spermatozoa per ejaculate) and teratospermic felids include: (i) the time required for sperm capacitation and the acrosome reaction to occur in vitro; (ii) culture media requirements for capacitation in vitro; (iii) phosphorylation patterns of tyrosine residues on sperm membrane proteins during capacitation; (iv) susceptibility to chilling-induced sperm membrane damage; (v) sensitivity to osmotic stress; (vi) stability of sperm DNA; (vii) sperm protamine composition; and (viii) fertilizing ability after intracytoplasmic sperm injection. In conclusion, (i) the felids (including wild species) are valuable for studying the functional significance of both pleiomorphic and normally formed spermatozoa from teratospermic donors, and (ii) the impact of Teratospermia is expressed at both macrocellular and subcellular levels.

  • the impact and potential etiology of Teratospermia in the domestic cat and its wild relatives
    Theriogenology, 2006
    Co-Authors: Budhan S Pukazhenthi, Jogayle Howard, Katrin Neubauer, Katarina Jewgenow, David E Wildt
    Abstract:

    Teratospermia (production of >60% morphologically abnormal sperm/ejaculate) is relatively common among various species in the family Felidae, which is comprised of 37 species. Over two decades of research in this area have produced a significant understanding of the phenotypic expression, its impacts on sperm function and etiology. There is good evidence suggesting that a reduction in genetic diversity contributes to this phenomenon. Results to date demonstrate that spermatozoa from teratospermic donors are compromised in the ability to undergo capacitation and the acrosome reaction, penetrate the zona-pellucida, fertilize conspecific oocytes and survive cryopreservation. Recent studies also reveal abnormalities in chromatin integrity in sperm from teratospermic donors, which, interestingly, fails to impact fertilization or embryo development after intracytoplasmic sperm injection. Through planned inbreeding studies, we now have established that teratospermic cats also produce more spermatozoa by virtue of more sperm producing tissue, more germ cells per Sertoli cell and reduced germ cell loss during spermatogenesis. Overall, it now is clear that gain in sperm quantity is achieved at the expense of sperm quality, suggesting an extensive disruption of normal testicular function in teratospermic donors. Preliminary studies on testicular gene expression in teratospermic cats have also revealed abnormal expression patterns. These findings have markedly increased our understanding of testis biology in the teratospermic donor and reaffirm the value of cats, including wild species, as models for studying novel regulatory mechanisms controlling spermatogenesis and spermiogenesis.

  • the phenomenon and significance of Teratospermia in felids
    Journal of reproduction and fertility, 2001
    Co-Authors: Budhan S Pukazhenthi, David E Wildt, Jogayle Howard
    Abstract:

    : The common domestic cat is an important research model for endangered felids, as well as for studying genetic dysfunctions, infectious diseases and infertility in humans. Especially significant is the trait of Teratospermia (ejaculation of 60% normal spermatozoa per ejaculate) and teratospermic felids include: (i) the time required for sperm capacitation and the acrosome reaction to occur in vitro; (ii) culture media requirements for capacitation in vitro; (iii) phosphorylation patterns of tyrosine residues on sperm membrane proteins during capacitation; (iv) susceptibility to chilling-induced sperm membrane damage; (v) sensitivity to osmotic stress; (vi) stability of sperm DNA; (vii) sperm protamine composition; and (viii) fertilizing ability after intracytoplasmic sperm injection. In conclusion, (i) the felids (including wild species) are valuable for studying the functional significance of both pleiomorphic and normally formed spermatozoa from teratospermic donors, and (ii) the impact of Teratospermia is expressed at both macrocellular and subcellular levels.

  • regulation of sperm function by protein tyrosine phosphorylation in diverse wild felid species
    Journal of Andrology, 1998
    Co-Authors: Budhan S Pukazhenthi, Julie A Long, Mary Ann Ottinger, D L Armstrong, David E Wildt, Jogayle Howard
    Abstract:

    : Protein tyrosine phosphorylation is associated with sperm capacitation and the acrosome reaction in several mammalian species. Changes in phosphorylation of a 95-kDa protein in human, mouse, and domestic cat spermatozoa are known to be influenced by capacitation and exposure to zona pellucida (ZP) proteins. We previously reported diminished phosphorylation of 95- and 160-kDa proteins in spermatozoa from teratospermic cats, compared with normospermic domestic cats. To determine if these proteins and mechanisms are present in other species in the phenotypically diverse Felidae family, we examined the relationship between tyrosine-phosphorylated sperm proteins and sperm morphology in the leopard cat (∼65% normal sperm/ejaculate), tiger (∼65%), clouded leopard (∼15%), and cheetah (∼30%). Furthermore, we investigated the involvement of cyclic adenosine monophosphate (cAMP) in the regulation of sperm protein tyrosine phosphorylation. Specifically, we assessed the following: 1) presence of tyrosine-phosphorylated proteins in sperm extracts; 2) changes in protein tyrosine phosphorylation after sperm capacitation and swim-up separation; 3) impact of tyrosine kinase inhibition on leopard cat sperm protein phosphorylation and ZP penetration; and 4) involvement of a cAMP-dependent pathway in the regulation of protein tyrosine phosphorylation. Immunoblotting analysis with anti-phosphotyrosine antibody (PY20) indicated that a 95-kDa protein was present in all four species. Additional phosphorylated proteins were detected in the leopard cat (145- and 175-kDa proteins), tiger (185-kDa protein), clouded leopard (160- and 190-kDa proteins), and cheetah (115- and 155-kDa proteins). Sperm capacitation in vitro increased phosphorylation of one or more proteins in the leopard cat, tiger and clouded leopard, but not in the cheetah. Although swim-up separation increased the proportion of morphologically normal spermatozoa in the clouded leopard and cheetah, no changes were observed in phosphorylation of the 95-kDa sperm protein. Thus, phosphorylation of the 95-kDa protein appeared to be related to the condition of Teratospermia. Exposing leopard cat spermatozoa to the tyrosine kinase inhibitor, tyrphostin, reduced (P < 0.05) phosphorylation of the 95-and 145-kDa proteins, as well as ZP penetration, without affecting sperm motility. Similarly, when spermatozoa were incubated in the presence of cAMP analogs or active and inactive stereoisomers of cAMP, phosphorylation of sperm proteins was either stimulated or inhibited. Together, these data suggest that protein tyrosine kinase mechanisms appear conserved within the family Felidae and are regulated by a cAMP/protein kinase A pathway.

  • Teratospermia in domestic cats compromises penetration of zona free hamster ova and cat zonae pellucidae
    Journal of Andrology, 1991
    Co-Authors: Jogayle Howard, Mitchell R Bush, David E Wildt
    Abstract:

    : The ability of spermatozoa to bind and penetrate zona-free hamster ova and the zonae pellucidae of domestic cat oocytes in vitro was compared between normospermic (greater than 60% structurally normal spermatozoa per ejaculate) and teratospermic (less than 40% normal spermatozoa per ejaculate) domestic cats. The effects of culture media (Biggers, Whitten, Whittingham [BWW] versus modified Krebs Ringer bicarbonate [mKRB]) and simple dilution (DR), ejaculate centrifugation, and either resuspension (NS) or swim-up processing (SU) on penetration also were examined. High percentages of structurally normal spermatozoa were bound to zona-pellucida-free hamster ova regardless of the morphological forms in the inseminant. Mean percent normal spermatozoa bound to ova in DR, NS, and SU sperm aliquots from teratospermic male cats were not different (P greater than 0.05) from similarly treated normospermic aliquots. However, the percent penetration of hamster ova by normospermic ejaculates (10.5%) was superior (P less than 0.05) to that of teratospermic ejaculates (2.8%). Although swim-up processing improved percent sperm motility, progressive motility, and normal morphology in teratospermic ejaculates (P less than 0.05), no difference was observed in ovum penetration among the DR-treated, NS-treated, and SU-treated spermatozoa (P greater than 0.05). Culture medium had no effect on sperm binding in the hamster assay, but ovum penetration rate by spermatozoa in the normospermic ejaculates was enhanced (P less than 0.05) using mKRB (13.5%) when compared with BWW (7.6%) medium. Spermatozoa from teratospermic cats were capable of binding and penetrating cat zonae; however, sperm-zona interaction (defined as percent of oocytes with spermatozoa binding to or penetrating into the zona) was different (P less than 0.05) between normospermic (65.3%) and teratospermic (24.2%) cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Budhan S Pukazhenthi - One of the best experts on this subject based on the ideXlab platform.

  • The phenomenon and significance of Teratospermia in felids.
    Journal of reproduction and fertility, 2020
    Co-Authors: Budhan S Pukazhenthi, David E Wildt, Jogayle Howard
    Abstract:

    The common domestic cat is an important research model for endangered felids, as well as for studying genetic dysfunctions, infectious diseases and infertility in humans. Especially significant is the trait of Teratospermia (ejaculation of < 40% morphologically normal spermatozoa) that commonly occurs in about 70% of the felid species or subspecies studied to date. Teratospermia, discovered more than two decades ago in the cheetah, is important: (i) for understanding the significance of sperm form and function; and (ii) because this condition is common in human males. It is apparent from IVF that deformed spermatozoa from teratospermic felids do not fertilize oocytes. However, the inability of spermatozoa from teratospermic males to bind, penetrate and decondense in the cytoplasm of the oocyte is not limited to malformed cells alone. Normal shaped spermatozoa from teratospermic males have reduced functional capacity. IVF results have consistently revealed a direct correlation between Teratospermia and compromised sperm function across felid species and populations. The most significant differences between normospermic (> 60% normal spermatozoa per ejaculate) and teratospermic felids include: (i) the time required for sperm capacitation and the acrosome reaction to occur in vitro; (ii) culture media requirements for capacitation in vitro; (iii) phosphorylation patterns of tyrosine residues on sperm membrane proteins during capacitation; (iv) susceptibility to chilling-induced sperm membrane damage; (v) sensitivity to osmotic stress; (vi) stability of sperm DNA; (vii) sperm protamine composition; and (viii) fertilizing ability after intracytoplasmic sperm injection. In conclusion, (i) the felids (including wild species) are valuable for studying the functional significance of both pleiomorphic and normally formed spermatozoa from teratospermic donors, and (ii) the impact of Teratospermia is expressed at both macrocellular and subcellular levels.

  • analysis of sertoli cell efficiency allows the differentiation between two fundamentally different forms of feline Teratospermia
    Theriogenology, 2013
    Co-Authors: K Jewgenow, Budhan S Pukazhenthi, Jennifer Schoen
    Abstract:

    Abstract Teratospermia is a common phenomenon within felid species and has been attributed to reduction in genetic diversity. Testes from teratospermic domestic cats show enhanced spermatogenesis accompanied by remarkably reduced germ cell apoptosis. In the present study we investigated whether free-range teratospermic tom cats exhibit a similar testicular phenotype as proven permanently teratospermic males. Randomly collected teratospermic cats were compared with normal (normospermic; >60% morphologically normal sperm per ejaculate) and a well-characterized population of permanently teratospermic domestic cats, with respect to their spermatogenic potential. Histomorphologic assessment of testes from randomly collected teratospermic cats revealed no differences compared with normospermic donors. These two groups, however, were both different from permanently teratospermic cats, which exhibit fewer Sertoli cells and increased numbers of round spermatids per tubule cross-section resulting in a remarkably increased Sertoli cell efficiency (ratio of round spermatids to Sertoli cells). In conclusion, we can distinguish at least two fundamentally different forms of feline Teratospermia. One subtype, found in most of the randomly collected tom cats, but not associated with altered quantitative spermatogenic parameters. Another subtype, found in all permanently teratospermic felids, is manifested by an impairment of Sertoli cell efficiency. We suggest that spermatogenic output should be analyzed before using random source domestic cats to study the phenomenon of Teratospermia.

  • the impact and potential etiology of Teratospermia in the domestic cat and its wild relatives
    Theriogenology, 2006
    Co-Authors: Budhan S Pukazhenthi, Jogayle Howard, Katrin Neubauer, Katarina Jewgenow, David E Wildt
    Abstract:

    Teratospermia (production of >60% morphologically abnormal sperm/ejaculate) is relatively common among various species in the family Felidae, which is comprised of 37 species. Over two decades of research in this area have produced a significant understanding of the phenotypic expression, its impacts on sperm function and etiology. There is good evidence suggesting that a reduction in genetic diversity contributes to this phenomenon. Results to date demonstrate that spermatozoa from teratospermic donors are compromised in the ability to undergo capacitation and the acrosome reaction, penetrate the zona-pellucida, fertilize conspecific oocytes and survive cryopreservation. Recent studies also reveal abnormalities in chromatin integrity in sperm from teratospermic donors, which, interestingly, fails to impact fertilization or embryo development after intracytoplasmic sperm injection. Through planned inbreeding studies, we now have established that teratospermic cats also produce more spermatozoa by virtue of more sperm producing tissue, more germ cells per Sertoli cell and reduced germ cell loss during spermatogenesis. Overall, it now is clear that gain in sperm quantity is achieved at the expense of sperm quality, suggesting an extensive disruption of normal testicular function in teratospermic donors. Preliminary studies on testicular gene expression in teratospermic cats have also revealed abnormal expression patterns. These findings have markedly increased our understanding of testis biology in the teratospermic donor and reaffirm the value of cats, including wild species, as models for studying novel regulatory mechanisms controlling spermatogenesis and spermiogenesis.

  • the phenomenon and significance of Teratospermia in felids
    Journal of reproduction and fertility, 2001
    Co-Authors: Budhan S Pukazhenthi, David E Wildt, Jogayle Howard
    Abstract:

    : The common domestic cat is an important research model for endangered felids, as well as for studying genetic dysfunctions, infectious diseases and infertility in humans. Especially significant is the trait of Teratospermia (ejaculation of 60% normal spermatozoa per ejaculate) and teratospermic felids include: (i) the time required for sperm capacitation and the acrosome reaction to occur in vitro; (ii) culture media requirements for capacitation in vitro; (iii) phosphorylation patterns of tyrosine residues on sperm membrane proteins during capacitation; (iv) susceptibility to chilling-induced sperm membrane damage; (v) sensitivity to osmotic stress; (vi) stability of sperm DNA; (vii) sperm protamine composition; and (viii) fertilizing ability after intracytoplasmic sperm injection. In conclusion, (i) the felids (including wild species) are valuable for studying the functional significance of both pleiomorphic and normally formed spermatozoa from teratospermic donors, and (ii) the impact of Teratospermia is expressed at both macrocellular and subcellular levels.

  • regulation of sperm function by protein tyrosine phosphorylation in diverse wild felid species
    Journal of Andrology, 1998
    Co-Authors: Budhan S Pukazhenthi, Julie A Long, Mary Ann Ottinger, D L Armstrong, David E Wildt, Jogayle Howard
    Abstract:

    : Protein tyrosine phosphorylation is associated with sperm capacitation and the acrosome reaction in several mammalian species. Changes in phosphorylation of a 95-kDa protein in human, mouse, and domestic cat spermatozoa are known to be influenced by capacitation and exposure to zona pellucida (ZP) proteins. We previously reported diminished phosphorylation of 95- and 160-kDa proteins in spermatozoa from teratospermic cats, compared with normospermic domestic cats. To determine if these proteins and mechanisms are present in other species in the phenotypically diverse Felidae family, we examined the relationship between tyrosine-phosphorylated sperm proteins and sperm morphology in the leopard cat (∼65% normal sperm/ejaculate), tiger (∼65%), clouded leopard (∼15%), and cheetah (∼30%). Furthermore, we investigated the involvement of cyclic adenosine monophosphate (cAMP) in the regulation of sperm protein tyrosine phosphorylation. Specifically, we assessed the following: 1) presence of tyrosine-phosphorylated proteins in sperm extracts; 2) changes in protein tyrosine phosphorylation after sperm capacitation and swim-up separation; 3) impact of tyrosine kinase inhibition on leopard cat sperm protein phosphorylation and ZP penetration; and 4) involvement of a cAMP-dependent pathway in the regulation of protein tyrosine phosphorylation. Immunoblotting analysis with anti-phosphotyrosine antibody (PY20) indicated that a 95-kDa protein was present in all four species. Additional phosphorylated proteins were detected in the leopard cat (145- and 175-kDa proteins), tiger (185-kDa protein), clouded leopard (160- and 190-kDa proteins), and cheetah (115- and 155-kDa proteins). Sperm capacitation in vitro increased phosphorylation of one or more proteins in the leopard cat, tiger and clouded leopard, but not in the cheetah. Although swim-up separation increased the proportion of morphologically normal spermatozoa in the clouded leopard and cheetah, no changes were observed in phosphorylation of the 95-kDa sperm protein. Thus, phosphorylation of the 95-kDa protein appeared to be related to the condition of Teratospermia. Exposing leopard cat spermatozoa to the tyrosine kinase inhibitor, tyrphostin, reduced (P < 0.05) phosphorylation of the 95-and 145-kDa proteins, as well as ZP penetration, without affecting sperm motility. Similarly, when spermatozoa were incubated in the presence of cAMP analogs or active and inactive stereoisomers of cAMP, phosphorylation of sperm proteins was either stimulated or inhibited. Together, these data suggest that protein tyrosine kinase mechanisms appear conserved within the family Felidae and are regulated by a cAMP/protein kinase A pathway.

Annick Delvigne - One of the best experts on this subject based on the ideXlab platform.

  • outcome of conventional ivf and icsi on sibling oocytes in patients suffering from Teratospermia
    International journal of fertility and women's medicine, 2006
    Co-Authors: B Becker, Evelyne Bertrand, Jeannine Van Hoeck, Godelieve Verhaegen, Serge Rozenberg, Annick Delvigne
    Abstract:

    OBJECTIVE: To compare the outcomes of conventional IVF and ICSI on sibling oocytes. DESIGN: Retrospective analysis. METHODS: Performance of ICSI on part of the oocytes and IVF on the remaining portion during the same cycle (sibling oocytes). PATIENTS: 135 couples (141 cycles) with male subfertility or with idiopathic infertility. RESULTS: Globally, the fertilization rate was not different between the ICSI and IVF, however, in patients with severe Teratospermia, it was higher after ICSI (56.2 vs. 44.2 %, p<0.05). The fertilization failure rate was higher in the IVF group than in the ICSI group, globally, (12.1 % vs 2.8 %, p = 0.005), as well in patients with severe Teratospermia. In the latter group, a higher number of top quality embryos were obtained after ICSI than after IVF. Of 57 cycles with severe Teratospermia, only ICSI-embryos were transferred in 24, while only IVF-embryos were transferred in 11, resulting respectively in 8 and 3 clinical pregnancies. CONCLUSION: This study underscores that ICSI is useful in patients with Teratospermia. Nevertheless, considering the chances of obtaining a successful fertilization after IVF and lower risk of chromosomal aberrations, we recommend performing both IVF and ICSI on sibling oocytes during the first treatment cycle in patients with Teratospermia.

  • Outcome of conventional IVF and ICSI on sibling oocytes in patients suffering from Teratospermia.
    International journal of fertility and women's medicine, 2006
    Co-Authors: B Becker, Evelyne Bertrand, Jeannine Van Hoeck, Godelieve Verhaegen, Serge Rozenberg, Annick Delvigne
    Abstract:

    OBJECTIVE: To compare the outcomes of conventional IVF and ICSI on sibling oocytes. DESIGN: Retrospective analysis. METHODS: Performance of ICSI on part of the oocytes and IVF on the remaining portion during the same cycle (sibling oocytes). PATIENTS: 135 couples (141 cycles) with male subfertility or with idiopathic infertility. RESULTS: Globally, the fertilization rate was not different between the ICSI and IVF, however, in patients with severe Teratospermia, it was higher after ICSI (56.2 vs. 44.2 %, p

Olubunmi Olapadeolaopa - One of the best experts on this subject based on the ideXlab platform.

  • is varicocelectomy indicated in subfertile men with clinical varicoceles who have asthenospermia or Teratospermia and normal sperm density
    International Journal of Urology, 2007
    Co-Authors: L I Okeke, Odunayo S Ikuerowo, Ifeanyi Chiekwe, Blessing Etukakpan, O B Shittu, Olubunmi Olapadeolaopa
    Abstract:

    Objective: Varicocele is the most common treatable cause of male infertility and is associated with progressive decline in testicular function. Varicocelectomy, a commonly performed operation, is indicated in infertile males with varicoceles who have oligospermia, asthenospermia, Teratospermia or a combination of these factors. It is not clear if varicocelectomy is indicated if the patients have normal sperm density associated with asthenospermia or Teratospermia. Methods: We reviewed 167 patients with varicocele-associated male infertility over a 7-year period (December 1999–November 2005). Preand post-varicocelectomy seminal fluid analyses, assessed using the World Health Organization criteria, were obtained at intervals of 4–6 months. Wilcoxon signed rank tests were used to evaluate for statistical significance and P 0.05 was considered significant. Results: The mean age of the patients and their spouses were 35 and 28 years, respectively. The mean duration of infertility was 3.2 years (range, 1.5–7.5). Oligospermia, Teratospermia, asthenospermia, oligospermia, asthenospermia and Teratospermia (OAT) syndrome and azoospermia were found preoperatively in 106 (63.5%), 58 (34.7%), 154 (92%), 118 (71%) and 15 (9%) patients, respectively. Overall, significant improvements in semen volume (P 0.05). In addition, azoospermic patients did not show significant improvement in any of the semen parameters (P > 0.05) Conclusion: No significant improvement in semen parameters may be obtained in patients with clinical varicocele and preoperative normospermia. It is possible that only patients with preoperative oligospermia may benefit from varicocelectomy. Larger multi-institutional studies are needed to determine more definitively if asthenospermia or Teratospermia in normospermic subfertile males with clinical varicoceles are in fact indications for varicocelectomy.