Cross-sexual Transfer

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Sex Determination ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Alternative Phenotypes ◽  
Opposite Sex ◽  
Critical Age ◽  
Sexual Traits ◽  
Discrete Traits ◽  
Dimorphic Species ◽  
Determination Mechanism

Distinctive male and female traits are perhaps the most familiar of all divergent specializations within species. In cross-sexual transfer, discrete traits that are expressed exclusively in one sex in an ancestral species appear in the opposite sex of descendants. An example is the expression of brood care by males in a lineage where ancestral females are the exclusive caretakers of the young, as in some voles (Thomas and Birney, 1979). Despite the prominence of sexual dimorphism and sex reversals in nature, and an early explicit treatment by Darwin, discussed in the next section, cross-sexual transfer is not often recognized as a major factor in the evolution of novelty (but see, on animals, Mayr, 1963, pp. 435-439; Mayr, 1970, p. 254; on plants, Iltis, 1983). When more widely investigated, cross-sexual transfer may prove to rival heterochrony and duplication as an important source of novelties in sexually dimorphic lineages. For this reason, I devote more attention here to cross-sexual transfer than to these other, well-established general patterns of change. The male and female of a sexually dimorphic species may be so different that it is easy to forget that each individual carries most or all of the genes necessary to produce the phenotype of the opposite sex. Sex determination, like caste determination and other switches between alternative phenotypes, depends on only a few genetic loci or, in many species, environmental factors (Bull, 1983). There is considerable flexibility in sex determination and facultative reversal in some taxa. Among fish, for example, there is even a species wherein sex is determined by juvenile size at a critical age (Francis and Barlow, 1993). The sex determination mechanism, whatever its nature, leads to a series of sex-limited responses, often coordinated by hormones and not necessarily all occurring at once. A distinguishing aspect of sexually dimorphic traits in adults is that there is often a close homology between the secondary sexual traits that are differently modified in the two sexes.

scholarly journals Genetic study of the production of sexually dimorphic cuticular hydrocarbons in relation with the sex-determination gene transformer in Drosophila melanogaster

2002 ◽  
Vol 79 (1) ◽  
pp. 23-40 ◽  
Author(s):  
FABRICE SAVARIT ◽  
JEAN-FRANÇOIS FERVEUR
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Determination ◽  
Cuticular Hydrocarbons ◽  
Fat Body ◽  
Sexually Dimorphic ◽  
Female Progeny ◽  
Male And Female ◽  
Good Relationship ◽  
Gal4 Expression ◽  
Sex Determination Mechanisms

In Drosophila melanogaster, the main cuticular hydrocarbons (HCs) are some of the pheromones involved in mate discrimination. These are sexually dimorphic in both their occurrence and their effects. The production of predominant HCs has been measured in male and female progeny of 220 PGal4 lines mated with the feminising UAS-transformer transgenic strain. In 45 lines, XY flies were substantially or totally feminised for their HCs. Surprisingly, XX flies of 14 strains were partially masculinised. Several of the PGal4 enhancer-trap variants screened here seem to interact with sex determination mechanisms involved in the control of sexually dimorphic characters. We also found a good relationship between the degree of HC transformation and GAL4 expression in oenocytes. The fat body was also involved in the switch of sexually dimorphic cuticular hydrocarbons but its effect was different between the sexes.

The Drosophila sex determination hierarchy modulates wingless and decapentaplegic signaling to deploy dachshund sex-specifically in the genital imaginal disc

Development ◽  
2001 ◽  
Vol 128 (9) ◽  
pp. 1643-1656 ◽  
Author(s):  
E.L. Keisman ◽  
B.S. Baker
Keyword(s):  
Transcription Factor ◽  
Sex Determination ◽  
Imaginal Disc ◽  
Sexually Dimorphic ◽  
Cell Specification ◽  
Male And Female ◽  
Developmental Program ◽  
Genital Discs ◽  
Genital Imaginal Disc ◽  
Female Genital

The integration of multiple developmental cues is crucial to the combinatorial strategies for cell specification that underlie metazoan development. In the Drosophila genital imaginal disc, which gives rise to the sexually dimorphic genitalia and analia, sexual identity must be integrated with positional cues, in order to direct the appropriate sexually dimorphic developmental program. Sex determination in Drosophila is controlled by a hierarchy of regulatory genes. The last known gene in the somatic branch of this hierarchy is the transcription factor doublesex (dsx); however, targets of the hierarchy that play a role in sexually dimorphic development have remained elusive. We show that the gene dachshund (dac) is differentially expressed in the male and female genital discs, and plays sex-specific roles in the development of the genitalia. Furthermore, the sex determination hierarchy mediates this sex-specific deployment of dac by modulating the regulation of dac by the pattern formation genes wingless (wg) and decapentaplegic (dpp). We find that the sex determination pathway acts cell-autonomously to determine whether dac is activated by wg signaling, as in females, or by dpp signaling, as in males.

scholarly journals The Snakeskin Gourami (Trichopodus pectoralis) Tends to Exhibit XX/XY Sex Determination

Fishes ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 43
Author(s):  
Thitipong Panthum ◽  
Nararat Laopichienpong ◽  
Ekaphan Kraichak ◽  
Worapong Singchat ◽  
Dung Ho My Nguyen ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sex Determination ◽  
Y Chromosome ◽  
Cytogenetic Analysis ◽  
Genotyping By Sequencing ◽  
Sexually Dimorphic ◽  
Determination System ◽  
Sex Determination System ◽  
Male Specific ◽  
Determination Mechanism

The snakeskin gourami (Trichopodus pectoralis) has a high meat yield and is one of the top five aquaculture freshwater fishes in Thailand. The species is not externally sexually dimorphic, and its sex determination system is unknown. Understanding the sex determination system of this species will contribute to its full-scale commercialization. In this study, a cytogenetic analysis did not reveal any between-sex differences in chromosomal patterns. However, we used genotyping-by-sequencing to identify 4 male-linked loci and 1 female-linked locus, indicating that the snakeskin gourami tends to exhibit an XX/XY sex determination system. However, we did not find any male-specific loci after filtering the loci for a ratio of 100:0 ratio of males:females. This suggests that the putative Y chromosome is young and that the sex determination region is cryptic. This approach provides solid information that can help identify the sex determination mechanism and potential sex determination regions in the snakeskin gourami, allowing further investigation of genetic improvements in the species.

scholarly journals A Macroevolutionary Perspective on Multiple Sexual Traits in the Phasianidae (Galliformes)

2011 ◽  
Vol 2011 ◽  
pp. 1-16 ◽  
Author(s):  
Rebecca T. Kimball ◽  
Colette M. St. Mary ◽  
Edward L. Braun
Keyword(s):  
Sexual Dimorphism ◽  
Competitive Ability ◽  
Sexually Dimorphic ◽  
Sexual Signals ◽  
Sexual Signaling ◽  
Multiple Signals ◽  
Alternative Models ◽  
Sexual Traits ◽  
Gains And Losses ◽  
Dimorphic Species

Traits involved in sexual signaling are ubiquitous among animals. Although a single trait appears sufficient to convey information, many sexually dimorphic species exhibit multiple sexual signals, which may be costly to signalers and receivers. Given that one signal may be enough, there are many microevolutionary hypotheses to explain the evolution of multiple signals. Here we extend these hypotheses to a macroevolutionary scale and compare those predictions to the patterns of gains and losses of sexual dimorphism in pheasants and partridges. Among nine dimorphic characters, including six intersexual signals and three indicators of competitive ability, all exhibited both gains and losses of dimorphism within the group. Although theories of intersexual selection emphasize gain and elaboration, those six characters exhibited greater rates of loss than gain; in contrast, the competitive traits showed a slight bias towards gains. The available models, when examined in a macroevolutionary framework, did not yield unique predictions, making it difficult to distinguish among them. Even with this limitation, when the predictions of these alternative models were compared with the heterogeneous patterns of evolution of dimorphism in phasianids, it is clear that many different selective processes have been involved in the evolution of sexual signals in this group.

Analysis of sex-linked, sequence-characterized amplified region markers in Salix eriocephala

2003 ◽  
Vol 33 (9) ◽  
pp. 1785-1790 ◽  
Author(s):  
L E Gunter ◽  
R F Kopp ◽  
R P McCord ◽  
G A Tuskan
Keyword(s):  
Sex Determination ◽  
Dna Markers ◽  
Goodness Of Fit ◽  
Salix Viminalis ◽  
Single Family ◽  
Goodness Of Fit Test ◽  
Male And Female ◽  
Sequence Characterized Amplified Region ◽  
Marker Loci ◽  
Determination Mechanism

Two DNA markers, sequence-characterized amplified region (SCAR) AE08780 and SCAR 354520, known to be linked to and flanking a putative sex determination locus in Salix viminalis L., were tested in another shrubform willow, Salix eriocephala Michx. Marker analysis of seven female and eight male S. eriocephala clones used to produce 34 fullsib families reveals that five pairs of parents are alternatively polymorphic relative to reciprocal male and female combinations for the two marker loci. A goodness-of-fit test of marker presence or absence and relationship to gender suggests that the occurrence of SCAR 354520 is not significantly different (χ2 = 3.18, df = 1, P > 0.05) from the expected ratio of marker presence:absence in the male and female progenies across all five families, indicating no relationship to gender. However, the occurrence of SCAR AE08780 differs significantly from expected (χ2 = 21.05, df = 1, P < 0.001) in the five families and seems to be linked to femaleness in S. eriocephala. Within a single family, 984 (n = 54), both markers show a significant deviation from expected at P < 0.01 (SCAR AE08780: χ2 = 11.37, df = 1; SCAR 354520: χ2 = 9.49, df = 1). These data support the hypothesis that there is an association between the markers and a locus associated with gender in two divergent species and that there may be a common sex determination mechanism in willow.

scholarly journals Bearded ladies: females suffer fitness consequences when bearing male traits

2013 ◽  
Vol 9 (6) ◽  
pp. 20130644 ◽  
Author(s):  
Lindsey Swierk ◽  
Tracy Langkilde
Keyword(s):  
Evolutionary Biology ◽  
Reproductive Output ◽  
Sexually Dimorphic ◽  
Sceloporus Undulatus ◽  
Secondary Sexual Traits ◽  
Intralocus Sexual Conflict ◽  
Fitness Consequences ◽  
Sexual Traits ◽  
Male Ornaments ◽  
Dimorphic Species

A central assumption in evolutionary biology is that females of sexually dimorphic species suffer costs when bearing male secondary sexual traits, such as ornamentation. Nevertheless, it is common in nature to observe females bearing rudimentary versions of male ornaments (e.g. ‘bearded ladies’), as ornaments can be under similar genetic control in both sexes. Here, we provide evidence that masculinized females incur both social and reproductive costs in nature. Male fence lizards ( Sceloporus undulatus ) discriminated against ornamented females during mate choice. Ornamented females had lower reproductive output, and produced eggs that were laid and hatched later than those of non-ornamented females. These findings support established theories of the evolution of sexual dimorphism and intralocus sexual conflict, and raise questions regarding the persistence of masculinizing ornamentation in females.

scholarly journals The Sex Determination Cascade in the Silkworm

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 315
Author(s):  
Xu Yang ◽  
Kai Chen ◽  
Yaohui Wang ◽  
Dehong Yang ◽  
Yongping Huang
Keyword(s):  
Sex Determination ◽  
Molecular Mechanisms ◽  
Future Research ◽  
Model Species ◽  
Male And Female ◽  
Master Regulators ◽  
Primary Signal ◽  
Basic Understanding ◽  
Female Specific ◽  
Working Mechanisms

In insects, sex determination pathways involve three levels of master regulators: primary signals, which determine the sex; executors, which control sex-specific differentiation of tissues and organs; and transducers, which link the primary signals to the executors. The primary signals differ widely among insect species. In Diptera alone, several unrelated primary sex determiners have been identified. However, the doublesex (dsx) gene is highly conserved as the executor component across multiple insect orders. The transducer level shows an intermediate level of conservation. In many, but not all examined insects, a key transducer role is performed by transformer (tra), which controls sex-specific splicing of dsx. In Lepidoptera, studies of sex determination have focused on the lepidopteran model species Bombyx mori (the silkworm). In B. mori, the primary signal of sex determination cascade starts from Fem, a female-specific PIWI-interacting RNA, and its targeting gene Masc, which is apparently specific to and conserved among Lepidoptera. Tra has not been found in Lepidoptera. Instead, the B. mori PSI protein binds directly to dsx pre-mRNA and regulates its alternative splicing to produce male- and female-specific transcripts. Despite this basic understanding of the molecular mechanisms underlying sex determination, the links among the primary signals, transducers and executors remain largely unknown in Lepidoptera. In this review, we focus on the latest findings regarding the functions and working mechanisms of genes involved in feminization and masculinization in Lepidoptera and discuss directions for future research of sex determination in the silkworm.

Social experience influences preferences in black ducks and mallards

1989 ◽  
Vol 67 (6) ◽  
pp. 1434-1438 ◽  
Author(s):  
Lynn M. Brodsky ◽  
C. Davison Ankney ◽  
Darrell G. Dennis
Keyword(s):  
Social Preferences ◽  
Anas Platyrhynchos ◽  
Social Experience ◽  
The Other ◽  
Captive Population ◽  
Male And Female ◽  
Potential Mate ◽  
The Social ◽  
Opposite Sex ◽  
Males And Females

The influence of social experience on the preferences for a potential mate in a captive population of black ducks, Anas rubripes, and mallards, Anas platyrhynchos, was examined. Birds were reared from hatching with conspecifics (i.e., female black ducks with male black ducks, female mallards with male mallards), or were cross-fostered with the other species (i.e., female black ducks with male mallards, female mallards with male black ducks). Preferences of individuals were tested in a chamber containing caged black ducks and mallards of the opposite sex. In over 90% (100/109) of the trials, males and females preferred the species that they were raised with since hatching, whether they were of the same species or not. These results demonstrate that social experience influences the social preferences of male and female black ducks and mallards.

Adults' Perceptions of Children's Independence and other Sex-Role Characteristics as a Function of Child's Gender Label

1978 ◽  
Vol 47 (3) ◽  
pp. 955-962 ◽  
Author(s):  
Nancy J. Bell ◽  
Kay Hibbs ◽  
Thomas Milholland
Keyword(s):  
College Students ◽  
Sex Role ◽  
Female College Students ◽  
Same Sex ◽  
Male And Female ◽  
Female College ◽  
Opposite Sex

Male and female college students were presented with a photograph labeled as a 5-yr.-old boy or girl and heard statements attributed to the child. They then rated the child on sex-role traits and responded to open-ended questions about the child. The primary findings involved sex of child by sex of adult interactions on ratings of independence and leadership: in both cases, same-sex children were rated higher than opposite-sex children. There was also some evidence that women having high contact with children rated the child more extremely on opposite-sex traits than did those with little contact.

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