scholarly journals Female‐specific resource limitation does not make the opportunity for selection more female biased

Evolution ◽  
2020 ◽  
Vol 74 (12) ◽  
pp. 2714-2724
Author(s):  
Ivain Martinossi‐Allibert ◽  
Johanna Liljestrand Rönn ◽  
Elina Immonen
Keyword(s):  
Resource Limitation ◽  
Female Specific ◽  
Opportunity For Selection

scholarly journals Female resource limitation does not make the opportunity for selection more female biased

2019 ◽  
Author(s):  
Ivain Martinossi-Allibert ◽  
Johanna Liljestrand Rönn ◽  
Elina Immonen
Keyword(s):  
Resource Limitation ◽  
Reproductive Age ◽  
Relative Fitness ◽  
Sex Bias ◽  
Common Environment ◽  
Physiological Conditions ◽  
Mean Fitness ◽  
Female Specific ◽  
Opportunity For Selection ◽  
Oviposition Sites

AbstractEnvironmental and physiological conditions affect how individual variation is expressed and translated into variance in fitness, the opportunity for natural selection. Competition for limiting resources can magnify variance in fitness and therefore selection, while abundance of resources should reduce it. But even in a common environment the strength of selection can be expected to differ across the sexes, as their fitness is often limited by different resources. Indeed most taxa show a greater opportunity for selection in males than in females, a bias often ascribed to intense competition among males for access to mating partners. This sex-bias could reverberate on many aspects of evolution, from speed of adaptation to genome evolution. It is unclear however, whether the sex-bias in opportunity for selection is robust to variations in environment or physiological condition that limit sex-specific resources. Here we test this in the model species C. maculatus by comparing female and male variance in relative fitness (opportunity for selection) under mate competition (i) with and without limitation of quality oviposition sites, and (ii) under delayed age at oviposition. Decreasing the abundance of the resource key to females or increasing their reproductive age was indeed challenging as shown by a reduction in mean fitness, however variance in fitness remained male-biased across the three treatments, with even an increased male-bias when females were limited by oviposition sites. This suggests that males remain the more variable sex independent of context, and that the opportunity for selection through males is indirectly affected by female-specific resource limitation.

scholarly journals Loss of p53 Causes Stochastic Aberrant X-Chromosome Inactivation and Female-Specific Neural Tube Defects

Cell Reports ◽  
2019 ◽  
Vol 27 (2) ◽  
pp. 442-454.e5 ◽  
Author(s):  
Alex R.D. Delbridge ◽  
Andrew J. Kueh ◽  
Francine Ke ◽  
Natasha M. Zamudio ◽  
Farrah El-Saafin ◽  
...  
Keyword(s):  
X Chromosome ◽  
Neural Tube ◽  
Neural Tube Defects ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Female Specific

scholarly journals Glucose tolerance female-specific QTL mapped in collaborative cross mice

2016 ◽  
Vol 28 (1-2) ◽  
pp. 20-30 ◽  
Author(s):  
Hanifa J. Abu-Toamih Atamni ◽  
Yaron Ziner ◽  
Richard Mott ◽  
Lior Wolf ◽  
Fuad A. Iraqi
Keyword(s):  
Glucose Tolerance ◽  
Collaborative Cross ◽  
Female Specific

scholarly journals Pleiotropic Roles of the Orthologue of the Drosophila melanogaster Intersex Gene in the Brown Planthopper

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 379
Author(s):  
Hou-Hong Zhang ◽  
Yu-Cheng Xie ◽  
Han-Jing Li ◽  
Ji-Chong Zhuo ◽  
Chuan-Xi Zhang
Keyword(s):  
Drosophila Melanogaster ◽  
Reproductive System ◽  
Splice Variants ◽  
Brown Planthopper ◽  
Nilaparvata Lugens ◽  
Vital Role ◽  
Sexually Dimorphic ◽  
Specific Product ◽  
Reproductive Ability ◽  
Female Specific

Intersex(ix), a gene involved in the sex-determining cascade of Drosophila melanogaster, works in concert with the female-specific product of doublesex (dsx) at the end of the hierarchy to implement the sex-specific differentiation of sexually dimorphic characters in female individuals. In this study, the ix homolog was identified in the brown planthopper (BPH), Nilaparvata lugens, which contained two splice variants expressed in both female and male insects. We found that Nlix played a vital role in the early nymphal development of BPH, showing an accumulated effect. RNAi-mediated knockdown of Nlix at 4th instar led to the external genital defects in both sexes, consequently resulting in the loss of reproductive ability in female and male individuals. After dsRNA injection, the males were normal on testes, while the females had defective ovarian development. Nlix was also required for early embryogenesis. Notably, when the dsNlix microinjection was performed in newly emerged females, the copulatory bursas were abnormally enlarged while the other tissues of the reproductive system developed normally. Our results demonstrated the pleiotropic roles of Nlix in embryogenesis and development of the reproductive system in a hemimetabolous insect species.

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.

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