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Frantisek Marec - One of the best experts on this subject based on the ideXlab platform.
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Absence of Sex Chromatin corresponds with a Sex-chromosome univalent in females of Trichoptera
European Journal of Entomology, 2013Co-Authors: Frantisek Marec, K. NovákAbstract:Five Trichoptera species, representing four different families of three suborders, have been examined for Sex Chromatin status in relation to their Sex chromosome system. These were Hydropsyche sp., Polycentropus flavomaculatus (Pictet), Rhyacophila sp., Anabolia furcata Brauer and Limnephilus decipiens (Kolenatý). None of the species displayed Sex-specific heteroChromatin in highly polyploid nuclei of the Malpighian tubule cells. Such Sex Chromatin is a characteristic trait of the heterogametic female Sex in the sister order Lepidoptera; it is derived from the heterologous Sex chromosome W. Hence, the absence of Sex Chromatin in somatic nuclei of Trichoptera females indicated the lack of a W chromosome in their karyotype. Correspondingly, diploid chromosome sets of the females consisted of an odd chromosome number, two sets of autosomes and one Sex chromosome Z. Thus, the Z/ZZ chromosome mechanism of Sex determination has been confirmed. In pachytene and postpachytene oocytes, the Z chromosome having no pairing partner formed a univalent. In Hydropsyche sp., the Z-univalent was distinct as a compact, positively heteropycnotic element. Whereas, in two other caddis-flies, P. flavomaculatus and L. decipiens, it formed a negatively heteropycnotic thread. In postpachytene nuclei of nurse cells of A. furcata, two sister chromatids of the Z chromosome separated as a result of chromosome degeneration and formed a negatively heteropycnotic pseudobivalent. The species-specific differences in pycnosis may reflect a transcriptional activity/inactivity of the Z chromosome during meiotic prophase. The absence of Sex Chromatin and the Sex chromosome system in Trichoptera are characters in common with the "primitive" Lepidoptera. This supports a hypothesis that the comm
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Sex Chromatin in Lepidoptera
The Quarterly review of biology, 1996Co-Authors: Walther Traut, Frantisek MarecAbstract:Like mammals, Lepidoptera possess female-specific Sex Chromatin. In a compilation of new and published data, 81 % of the 238 investigated Lepidoptera species display one or more heteroChromatin bodies infemale somatic interphase cells, but not in male cells. In contrast with the similar phenomenon in mammals, this Sex-specific heteroChromatin does notfunction as a dosage compensation mechanism. Most Lepidoptera have a WZ/ZZ Sex chromosome mechanism, and the Sex Chromatin is derived from the univalent W Sex chromosome. Sex Chromatin is regarded as an indicator of an advanced stage of Wchromosome evolution. In species with a Z/ZZ Sex chromosome mechanism, loss of the Wchromosome is accompanied by loss ofthefemale-specific heteroChromatin. Since Sex Chromatin can be discerned easily in interphase nuclei, and especially so in the highly polyploid somatic cells, it is a useful marker for diagnosing chromosomal Sex of embryos and larvae, and of identifying Sex chromosome aberrations in mutagenesis screens. All species with Sex Chromatin belong to theDitrysia, the main clade of Lepidoptera that contains more than 98 % of all extant species. Sex Chromatin has not been reportedfor clades that branched off earlier. The nonditrysian clades share this character with Trichoptera, a sister group of the Lepidoptera. We propose that Lepidoptera originally had a Z/ZZ Sex chromosome mechanism like Trichoptera; the WZ/ZZ Sex chromosome mechanism evolved later in the ditrysian branch of Lepidoptera. Secondary losses of the W chromosome account for the sporadically occurring Z/ZZ Sex chromosome systems in ditrysianfamilies. The lepidopteran Sex Chromatin, therefore, appears to mirror thefull evolutionary life cycle of a univalent Sex chromosomefrom its birth through heteroChromatinization to sporadic loss.
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Sex Chromatin in Lepidoptera
The Quarterly review of biology, 1996Co-Authors: Walther Traut, Frantisek MarecAbstract:Like mammals, Lepidoptera possess female-specific Sex Chromatin. In a compilation of new and published data, 81% 238 investigated Lepidoptera species display one or more heteroChromatin bodies in female somatic interphase cells, but not in male cells. In contrast with the similar phenomenon in mammals, this Sex-specific heteroChromatin does not function as a dosage compensation mechanism. Most Lepidoptera have a WZ/ZZ Sex chromosome mechanism, and the Sex Chromatin is derived from the univalent W Sex chromosome. Sex Chromatin is regarded as an indicator of an advanced stage of W chromosome evolution. In species with a Z/ZZ Sex chromosome mechanism, loss of the W chromosome is accompanied by loss of the female-specific heteroChromatin. Since Sex Chromatin can be discerned easily in interphase nuclei, and especially so in the highly polyploid somatic cells, it is a useful marker for diagnosing chromosomal Sex of embryos and larvae, and of identifying Sex chromosome aberrations in mutagenesis screens. All sp...
Walther Traut - One of the best experts on this subject based on the ideXlab platform.
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Sex Chromatin in Lepidoptera
The Quarterly review of biology, 1996Co-Authors: Walther Traut, Frantisek MarecAbstract:Like mammals, Lepidoptera possess female-specific Sex Chromatin. In a compilation of new and published data, 81 % of the 238 investigated Lepidoptera species display one or more heteroChromatin bodies infemale somatic interphase cells, but not in male cells. In contrast with the similar phenomenon in mammals, this Sex-specific heteroChromatin does notfunction as a dosage compensation mechanism. Most Lepidoptera have a WZ/ZZ Sex chromosome mechanism, and the Sex Chromatin is derived from the univalent W Sex chromosome. Sex Chromatin is regarded as an indicator of an advanced stage of Wchromosome evolution. In species with a Z/ZZ Sex chromosome mechanism, loss of the Wchromosome is accompanied by loss ofthefemale-specific heteroChromatin. Since Sex Chromatin can be discerned easily in interphase nuclei, and especially so in the highly polyploid somatic cells, it is a useful marker for diagnosing chromosomal Sex of embryos and larvae, and of identifying Sex chromosome aberrations in mutagenesis screens. All species with Sex Chromatin belong to theDitrysia, the main clade of Lepidoptera that contains more than 98 % of all extant species. Sex Chromatin has not been reportedfor clades that branched off earlier. The nonditrysian clades share this character with Trichoptera, a sister group of the Lepidoptera. We propose that Lepidoptera originally had a Z/ZZ Sex chromosome mechanism like Trichoptera; the WZ/ZZ Sex chromosome mechanism evolved later in the ditrysian branch of Lepidoptera. Secondary losses of the W chromosome account for the sporadically occurring Z/ZZ Sex chromosome systems in ditrysianfamilies. The lepidopteran Sex Chromatin, therefore, appears to mirror thefull evolutionary life cycle of a univalent Sex chromosomefrom its birth through heteroChromatinization to sporadic loss.
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Sex Chromatin in Lepidoptera
The Quarterly review of biology, 1996Co-Authors: Walther Traut, Frantisek MarecAbstract:Like mammals, Lepidoptera possess female-specific Sex Chromatin. In a compilation of new and published data, 81% 238 investigated Lepidoptera species display one or more heteroChromatin bodies in female somatic interphase cells, but not in male cells. In contrast with the similar phenomenon in mammals, this Sex-specific heteroChromatin does not function as a dosage compensation mechanism. Most Lepidoptera have a WZ/ZZ Sex chromosome mechanism, and the Sex Chromatin is derived from the univalent W Sex chromosome. Sex Chromatin is regarded as an indicator of an advanced stage of W chromosome evolution. In species with a Z/ZZ Sex chromosome mechanism, loss of the W chromosome is accompanied by loss of the female-specific heteroChromatin. Since Sex Chromatin can be discerned easily in interphase nuclei, and especially so in the highly polyploid somatic cells, it is a useful marker for diagnosing chromosomal Sex of embryos and larvae, and of identifying Sex chromosome aberrations in mutagenesis screens. All sp...
Sudha Chhabra - One of the best experts on this subject based on the ideXlab platform.
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Sex Chromatin positive cells in the buccal smears of normal newborn females
2013Co-Authors: Usha Verma, D S Chowdhary, Sudha ChhabraAbstract:The present study has been conducted on normal 100 newborn females, born at Umaid Hospital, Dr. S. N. Medical College, Jodhpur (Rajasthan). The aim of the study was to find out frequency of Sex Chromatin positive cells in buccal smear of normal newborn females and their relation with the birth weight. The slides were prepared from the buccal smears and stained by the Carbol Fuschin method. The Sex Chromatin bodies were present in range of 3-11% with an average of 6.5% ± 0.3%. We found no relation between the number of Sex Chromatin positive cells and the birth weight of newborn females.
Usha Verma - One of the best experts on this subject based on the ideXlab platform.
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Sex Chromatin positive cells in the buccal smears of normal newborn females
2013Co-Authors: Usha Verma, D S Chowdhary, Sudha ChhabraAbstract:The present study has been conducted on normal 100 newborn females, born at Umaid Hospital, Dr. S. N. Medical College, Jodhpur (Rajasthan). The aim of the study was to find out frequency of Sex Chromatin positive cells in buccal smear of normal newborn females and their relation with the birth weight. The slides were prepared from the buccal smears and stained by the Carbol Fuschin method. The Sex Chromatin bodies were present in range of 3-11% with an average of 6.5% ± 0.3%. We found no relation between the number of Sex Chromatin positive cells and the birth weight of newborn females.
Rita Ivanauskaitė - One of the best experts on this subject based on the ideXlab platform.
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Sex Chromatin in Peripheral Blood Neutrophils and Sex Determination
Case Reports in Clinical Medicine, 2018Co-Authors: Zoja Miknienė, Rita IvanauskaitėAbstract:The objective of this paper is to review in what forms Sex Chromatin can appear in peripheral blood neutrophils and how Sex determination can be done using Sex Chromatin appendages. Sex Chromatin is an approximately 1 micron clump of Chromatin seen usually at the periphery of female nuclei in certain tissues and called “Barr body” and as a drumstick in polymor phonuclear neutrophils nuclei in the blood smears. Sex Chromatin is derived from one of the two X chromosomes in the female which replicates its deoxyribonucleic acid much later than the other and is thus positively heteropyknotic. In 1954, Davidson and Smith were the first to identify and report the presence of neutrophil drumsticks and nonspecific appendages and their differences in Sexes. The inactive X chromosome in neutrophils appears in one of the five forms: drumsticks, racquet forms, sessile nodules, small clubs and minor lobes. Only drumstick appendage is Sex-specific and considered for Sex diagnosis. For Sex determination, drumsticks are significantly higher in females than in males (p < 0.001).
