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Clifford Tabin - One of the best experts on this subject based on the ideXlab platform.
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A relative shift in cloacal location repositions external Genitalia in amniote evolution
Nature, 2014Co-Authors: Patrick Tschopp, Emma Sherratt, Thomas Sanger, Anna Groner, Ariel Aspiras, Olivier Pourquié, Jerome Gros, Clifford TabinAbstract:The move of vertebrates to a terrestrial lifestyle required major adaptations in their locomotory apparatus and reproductive organs. While the fin-to-limb transition has received considerable attention, little is known about the developmental and evolutionary origins of external Genitalia. Similarities in gene expression have been interpreted as a potential evolutionary link between the limb and genitals; however, no underlying developmental mechanism has been identified. We re-examined this question using micro-computed tomography, lineage tracing in three amniote clades, and RNA-sequencing-based transcriptional profiling. Here we show that the developmental origin of external Genitalia has shifted through evolution, and in some taxa limbs and genitals share a common primordium. In squamates, the Genitalia develop directly from the budding hindlimbs, or the remnants thereof, whereas in mice the genital tubercle originates from the ventral and tail bud mesenchyme. The recruitment of different cell populations for genital outgrowth follows a change in the relative position of the cloaca, the Genitalia organizing centre. Ectopic grafting of the cloaca demonstrates the conserved ability of different mesenchymal cells to respond to these Genitalia-inducing signals. Our results support a limb-like developmental origin of external Genitalia as the ancestral condition. Moreover, they suggest that a change in the relative position of the cloacal signalling centre during evolution has led to an altered developmental route for external Genitalia in mammals, while preserving parts of the ancestral limb molecular circuitry owing to a common evolutionary origin.
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A relative shift in cloacal location repositions external Genitalia in amniote evolution
Nature, 2014Co-Authors: Patrick Tschopp, Thomas J Sanger, Emma Sherratt, Ariel Aspiras, Olivier Pourquié, Jerome Gros, Anna C. Groner, Jimmy K. Hu, Clifford TabinAbstract:It has been known for some time that limbs share at least some of their molecular patterning mechanisms with external Genitalia. Clifford Tabin and colleagues examine the connection in a variety of amniotes (land vertebrates excluding amphibia) and show that the connection is more varied than one might imagine. In squamates (snakes and lizards) for example, the external Genitalia are made from the tissues that the hindlimbs (or rudiments thereof) originate from, whereas in mammals they are made from tail-bud tissue. The determinant, it seems, is the relative position on the body axis of the cloaca — the primitively conjoint opening of urinary, digestive and reproductive tracts — which is an important 'organizing centre' in development. The move of vertebrates to a terrestrial lifestyle required major adaptations in their locomotory apparatus and reproductive organs. While the fin-to-limb transition has received considerable attention^ 1 , 2 , little is known about the developmental and evolutionary origins of external Genitalia. Similarities in gene expression have been interpreted as a potential evolutionary link between the limb and genitals^ 3 , 4 , 5 , 6 ; however, no underlying developmental mechanism has been identified. We re-examined this question using micro-computed tomography, lineage tracing in three amniote clades, and RNA-sequencing-based transcriptional profiling. Here we show that the developmental origin of external Genitalia has shifted through evolution, and in some taxa limbs and genitals share a common primordium. In squamates, the Genitalia develop directly from the budding hindlimbs, or the remnants thereof, whereas in mice the genital tubercle originates from the ventral and tail bud mesenchyme. The recruitment of different cell populations for genital outgrowth follows a change in the relative position of the cloaca, the Genitalia organizing centre. Ectopic grafting of the cloaca demonstrates the conserved ability of different mesenchymal cells to respond to these Genitalia-inducing signals. Our results support a limb-like developmental origin of external Genitalia as the ancestral condition. Moreover, they suggest that a change in the relative position of the cloacal signalling centre during evolution has led to an altered developmental route for external Genitalia in mammals, while preserving parts of the ancestral limb molecular circuitry owing to a common evolutionary origin. It has been known for some time that limbs share at least some of their molecular patterning mechanism with external Genitalia; here, this connection is examined in a variety of species, revealing that once-shared developmental trajectories could help to explain the observed patterning similarities.
William G Eberhard - One of the best experts on this subject based on the ideXlab platform.
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genitalic stridulation during copulation in a species of crane fly tipula bellardina sp diptera tipulidae
Revista De Biologia Tropical, 2009Co-Authors: William G Eberhard, Jon K GelhausAbstract:The male Genitalia of many animal groups have elaborate and species-specific forms. One hypothesis to explain why this is so is that male Genitalia function as stimulatory devices that are under sexual selection by cryptic female choice. This report is based on a videotaped observation of a single male of an unidentified spe- cies of Tipula (Bellarina) from San Jose Province, Costa Rica. A male crane fly stridulated (produced vibrations) during copulation using sustained and stereotyped movements of file and scraper structures on his Genitalia. Males of related species have similar file and scraper structures on their Genitalia, suggesting that they probably also stridulate during copulation. Rev. Biol. Trop. 57 (Suppl. 1): 251-256. Epub 2009 November 30.
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copulatory dialogue female spiders sing during copulation to influence male genitalic movements
Animal Behaviour, 2006Co-Authors: Alfredo V Peretti, William G Eberhard, Daniel R BricenoAbstract:Female behaviour during copulation that could function as communication with the male is probably more common than previously appreciated, but its functional significance remains little studied. Stridulation during copulation by the female of the spider Physocylus globosus (Taczanowski, 1873), documented here for the first time, is common and noncoercive, thus permitting simple tests regarding its possible function. Males squeezed females rhythmically with their enlarged, powerful Genitalia throughout copulation, and more male genitalic squeezes were associated with increased paternity when females mated with two males. Contextual associations suggest that female stridulation represents attempts to induce the male to interrupt genitalic squeezes: female stridulation was more common when the male was squeezing her; females were more likely to stridulate when individual male squeezes were longer, and when the male had not responded to a previous stridulation by loosening a squeeze; females were more likely to refrain from stridulating when the male loosened a squeeze; males were more likely to loosen squeezes when the female stridulated; and female stridulation was associated with rejection of males in other contexts. Males that responded to female stridulation more consistently by loosening their squeezes obtained greater paternity. Possible female communicatory behaviour during copulation is known in other species. Future attention to female as well as to male behaviour, and to possible dialogues during copulation, promises to be valuable in understanding sexual interactions.
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one size fits all relationships between the size and degree of variation in Genitalia and other body parts in twenty species of insects and spiders
Evolution, 1998Co-Authors: William G Eberhard, Bernhard A Huber, Rafael Lucas S Rodriguez, Daniel R Briceno, Isabel Salas, Viterbo RodriguezAbstract:Hypotheses regarding the function of elaborate male Genitalia were tested in a sample of insects and spiders by comparing their allometric values (slopes in log-log regressions on indicators of body size) with those of other body parts. Male Genitalia consistently had lower slopes than other body parts. Perhaps as a consequence of this pattern, genitalic size also tended, though less consistently, to have lower coefficients of variation than did the size of other body parts. The morphological details of coupling between males and females in several species clearly indicated that selection favoring mechanical fit is not responsible for these trends. Sexual selection on male courtship structures that are brought into contact with females in precise ways may favor relatively low allometric values, in contrast to the high values seen in the other sexually selected characters (usually visual display devices) that have been studied previously, because a female's own size will influence her perception of the contact courtship devices of a male.
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copulatory courtship and morphology of genitalic coupling in seven phyllophaga species coleoptera melolonthidae
Journal of Natural History, 1993Co-Authors: William G EberhardAbstract:Males in six of seven species of Phyllophaga perform apparent courtship behaviour during copulation. As predicted by the hypothesis that such copulatory courtship is under sexual selection by female choice, behavioural details differ between species. The modified male abdominal sternites, which rub against the female's pygidium during copulation and whose morphology also differs between species, and the flattened, setose tarsi of males of one species probably function as contact courtship devices during copulatory courtship. Observations of events inside copulating beetles were made through the semi-transparent abdominal sternites of females and male Genitalia in three species. They revealed cryptic genitalic thrusting behaviour of male Genitalia within the female which occurred even when there was little or no external movement of the male Genitalia. Dissections of pairs frozen in copula demonstrated that males transfer large quantities of material to females during copulation that is not physically rela...
Maxi Polihronakis Richmond - One of the best experts on this subject based on the ideXlab platform.
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the function and evolution of male and female Genitalia in phyllophaga harris scarab beetles coleoptera scarabaeidae
Journal of Evolutionary Biology, 2016Co-Authors: Maxi Polihronakis Richmond, J. Park, Charles S. HenryAbstract:: Genitalia diversity in insects continues to fuel investigation of the function and evolution of these dynamic structures. Whereas most studies have focused on variation in male Genitalia, an increasing number of studies on female Genitalia have uncovered comparable diversity among females, but often at a much finer morphological scale. In this study, we analysed the function and evolution of male and female Genitalia in Phyllophaga scarab beetles, a group in which both sexes exhibit genitalic diversity. To document the interaction between male and female structures during mating, we dissected flash-frozen mating pairs from three Phyllophaga species and investigated fine-scale morphology using SEM. We then reconstructed ancestral character states using a species tree inferred from mitochondrial and nuclear loci to elucidate and compare the evolutionary history of male and female Genitalia. Our dissections revealed an interlocking mechanism of the female pubic process and male parameres that appears to improve the mechanical fit of the copulatory position. The comparative analyses, however, did not support coevolution of male and female structures and showed more erratic evolution of the female Genitalia relative to males. By studying a group that exhibits obvious female genitalic diversity, we were able to demonstrate the relevance of female reproductive morphology in studies of male genital diversity.
Goran Arnqvist - One of the best experts on this subject based on the ideXlab platform.
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Comparative evidence for the evolution of Genitalia by sexual selection
Nature, 1998Co-Authors: Goran ArnqvistAbstract:Rapid divergent evolution of male Genitalia is one of the most general evolutionary trends in animals with internal fertilization; the shapes of genital traits often provide the only reliable characters for species identification1. Yet the evolutionary processes responsible for this pattern remain obscure. The long-standing lock-and-key hypothesis, still popular among taxonomists, suggests that Genitalia evolve by pre-insemination hybridization avoidance; that is, hybrid inferiority drives the evolution of male Genitalia with a proper mechanical fit to female Genitalia. The sexual selection hypothesis2,3, in contrast, proposes that divergent evolution of Genitalia is the result of sexual selection, brought about by variation in postinsemination paternity success among males. Here, by comparing pairs of related clades of insects that differ in mating system, I assess how the opportunity for postmating sexual selection affects the rate of divergent evolution of male Genitalia. Genital evolution is more than twice as divergent in groups in which females mate several times than in groups in which females mate only once. This pattern is not found for other morphological traits. These findings provide strong empirical evidence in favour of a postmating sexual selection mechanism of genital evolution.
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the evolution of animal Genitalia distinguishing between hypotheses by single species studies
Biological Journal of The Linnean Society, 1997Co-Authors: Goran ArnqvistAbstract:Rapid evolution of Genitalia is one of the most general patterns of morphological diversification in animals. Despite its generality, the causes of this evolutionary trend remain obscure. Several alternative hypotheses have been suggested to account for the evolution of Genitalia (notably the lock-and-key, pleiotropism, and sexual selection hypotheses). Here, I argue that thorough intraspecific studies are the key to gaining insight into the patterns and processes of genitalic evolution. Critical assumptions and predictions that may be used to distinguish between the different hypotheses are identified and discussed. However, current knowledge of selection on Genitalia, or even of the degree of phenotypic and genotypic variability of genital morphology, is highly limited, allowing only a very tentative assessment of the various hypotheses. In-depth single species studies of current patterns and processes of selection on Genitalia are badly needed, and a single species research program is briefly outlined.
Patrick Tschopp - One of the best experts on this subject based on the ideXlab platform.
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A relative shift in cloacal location repositions external Genitalia in amniote evolution
Nature, 2014Co-Authors: Patrick Tschopp, Emma Sherratt, Thomas Sanger, Anna Groner, Ariel Aspiras, Olivier Pourquié, Jerome Gros, Clifford TabinAbstract:The move of vertebrates to a terrestrial lifestyle required major adaptations in their locomotory apparatus and reproductive organs. While the fin-to-limb transition has received considerable attention, little is known about the developmental and evolutionary origins of external Genitalia. Similarities in gene expression have been interpreted as a potential evolutionary link between the limb and genitals; however, no underlying developmental mechanism has been identified. We re-examined this question using micro-computed tomography, lineage tracing in three amniote clades, and RNA-sequencing-based transcriptional profiling. Here we show that the developmental origin of external Genitalia has shifted through evolution, and in some taxa limbs and genitals share a common primordium. In squamates, the Genitalia develop directly from the budding hindlimbs, or the remnants thereof, whereas in mice the genital tubercle originates from the ventral and tail bud mesenchyme. The recruitment of different cell populations for genital outgrowth follows a change in the relative position of the cloaca, the Genitalia organizing centre. Ectopic grafting of the cloaca demonstrates the conserved ability of different mesenchymal cells to respond to these Genitalia-inducing signals. Our results support a limb-like developmental origin of external Genitalia as the ancestral condition. Moreover, they suggest that a change in the relative position of the cloacal signalling centre during evolution has led to an altered developmental route for external Genitalia in mammals, while preserving parts of the ancestral limb molecular circuitry owing to a common evolutionary origin.
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A relative shift in cloacal location repositions external Genitalia in amniote evolution
Nature, 2014Co-Authors: Patrick Tschopp, Thomas J Sanger, Emma Sherratt, Ariel Aspiras, Olivier Pourquié, Jerome Gros, Anna C. Groner, Jimmy K. Hu, Clifford TabinAbstract:It has been known for some time that limbs share at least some of their molecular patterning mechanisms with external Genitalia. Clifford Tabin and colleagues examine the connection in a variety of amniotes (land vertebrates excluding amphibia) and show that the connection is more varied than one might imagine. In squamates (snakes and lizards) for example, the external Genitalia are made from the tissues that the hindlimbs (or rudiments thereof) originate from, whereas in mammals they are made from tail-bud tissue. The determinant, it seems, is the relative position on the body axis of the cloaca — the primitively conjoint opening of urinary, digestive and reproductive tracts — which is an important 'organizing centre' in development. The move of vertebrates to a terrestrial lifestyle required major adaptations in their locomotory apparatus and reproductive organs. While the fin-to-limb transition has received considerable attention^ 1 , 2 , little is known about the developmental and evolutionary origins of external Genitalia. Similarities in gene expression have been interpreted as a potential evolutionary link between the limb and genitals^ 3 , 4 , 5 , 6 ; however, no underlying developmental mechanism has been identified. We re-examined this question using micro-computed tomography, lineage tracing in three amniote clades, and RNA-sequencing-based transcriptional profiling. Here we show that the developmental origin of external Genitalia has shifted through evolution, and in some taxa limbs and genitals share a common primordium. In squamates, the Genitalia develop directly from the budding hindlimbs, or the remnants thereof, whereas in mice the genital tubercle originates from the ventral and tail bud mesenchyme. The recruitment of different cell populations for genital outgrowth follows a change in the relative position of the cloaca, the Genitalia organizing centre. Ectopic grafting of the cloaca demonstrates the conserved ability of different mesenchymal cells to respond to these Genitalia-inducing signals. Our results support a limb-like developmental origin of external Genitalia as the ancestral condition. Moreover, they suggest that a change in the relative position of the cloacal signalling centre during evolution has led to an altered developmental route for external Genitalia in mammals, while preserving parts of the ancestral limb molecular circuitry owing to a common evolutionary origin. It has been known for some time that limbs share at least some of their molecular patterning mechanism with external Genitalia; here, this connection is examined in a variety of species, revealing that once-shared developmental trajectories could help to explain the observed patterning similarities.
