@article{20330,
  abstract     = {The evolution of sexual dimorphism (the difference in average trait values between females and males, SD), is often thought to be constrained by shared genetic architecture between the sexes. Indeed, it is commonly expected that SD should negatively correlate with the intersex correlation (the genetic correlation between effects of segregating variants in females and males, r fm), either because (1) traits with ancestrally low r fm are less constrained in their ability to respond to sex-specific selection and thus evolve to be more dimorphic, or because (2) sex-specific selection, driving sexual dimorphism evolution, also acts to reduce r fm. Despite the intuitive appeal and prominence of these ideas, their generality and the conditions in which they hold remain unclear. Here, we develop models incorporating sex-specific stabilizing selection, mutation and genetic drift to examine the relationship between r fm and SD. We show that the two commonly-discussed mechanisms with the potential to generate a negative correlation between SD and r fm could just as easily generate a positive association, since the standard line of reasoning hinges on a hidden assumption that sex-specific adaptation more frequently favors increased dimorphism than reduced dimorphism. Our results provide, to our knowledge, the first mechanistic framework for understanding the conditions under which a correlation between r fm and SD may arise and offer a compelling explanation for inconsistent empirical evidence. We also make the intriguing observation that—even when selection between the two sexes is identical—drift generates nonzero SD. We quantify this effect and discuss its significance.},
  author       = {Puixeu Sala, Gemma and Hayward, Laura},
  issn         = {1943-2631},
  journal      = {Genetics},
  number       = {3},
  publisher    = {Oxford University Press},
  title        = {{The relationship between sexual dimorphism and intersex correlation: Do models support intuition?}},
  doi          = {10.1093/genetics/iyaf175},
  volume       = {231},
  year         = {2025},
}

@phdthesis{14058,
  abstract     = {Females and males across species are subject to divergent selective pressures arising
from di↵erent reproductive interests and ecological niches. This often translates into a
intricate array of sex-specific natural and sexual selection on traits that have a shared
genetic basis between both sexes, causing a genetic sexual conflict. The resolution of
this conflict mostly relies on the evolution of sex-specific expression of the shared genes,
leading to phenotypic sexual dimorphism. Such sex-specific gene expression is thought
to evolve via modifications of the genetic networks ultimately linked to sex-determining
transcription factors. Although much empirical and theoretical evidence supports this
standard picture of the molecular basis of sexual conflict resolution, there still are a
few open questions regarding the complex array of selective forces driving phenotypic
di↵erentiation between the sexes, as well as the molecular mechanisms underlying sexspecific adaptation. I address some of these open questions in my PhD thesis.
First, how do patterns of phenotypic sexual dimorphism vary within populations,
as a response to the temporal and spatial changes in sex-specific selective forces? To
tackle this question, I analyze the patterns of sex-specific phenotypic variation along
three life stages and across populations spanning the whole geographical range of Rumex
hastatulus, a wind-pollinated angiosperm, in the first Chapter of the thesis.
Second, how do gene expression patterns lead to phenotypic dimorphism, and what
are the molecular mechanisms underlying the observed transcriptomic variation? I
address this question by examining the sex- and tissue-specific expression variation in
newly-generated datasets of sex-specific expression in heads and gonads of Drosophila
melanogaster. I additionally used two complementary approaches for the study of the
genetic basis of sex di↵erences in gene expression in the second and third Chapters of
the thesis.
Third, how does intersex correlation, thought to be one of the main aspects constraining the ability for the two sexes to decouple, interact with the evolution of sexual
dimorphism? I develop models of sex-specific stabilizing selection, mutation and drift
to formalize common intuition regarding the patterns of covariation between intersex
correlation and sexual dimorphism in the fourth Chapter of the thesis.
Alltogether, the work described in this PhD thesis provides useful insights into the
links between genetic, transcriptomic and phenotypic layers of sex-specific variation,
and contributes to our general understanding of the dynamics of sexual dimorphism
evolution.},
  author       = {Puixeu Sala, Gemma},
  isbn         = {978-3-99078-035-0},
  issn         = {2663-337X},
  pages        = {230},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{The molecular basis of sexual dimorphism: Experimental and theoretical characterization of phenotypic, transcriptomic and genetic patterns of sex-specific adaptation}},
  doi          = {10.15479/at:ista:14058},
  year         = {2023},
}

@article{14077,
  abstract     = {The regulatory architecture of gene expression is known to differ substantially between sexes in Drosophila, but most studies performed
so far used whole-body data and only single crosses, which may have limited their scope to detect patterns that are robust across tissues
and biological replicates. Here, we use allele-specific gene expression of parental and reciprocal hybrid crosses between 6 Drosophila
melanogaster inbred lines to quantify cis- and trans-regulatory variation in heads and gonads of both sexes separately across 3 replicate
crosses. Our results suggest that female and male heads, as well as ovaries, have a similar regulatory architecture. On the other hand,
testes display more and substantially different cis-regulatory effects, suggesting that sex differences in the regulatory architecture that
have been previously observed may largely derive from testis-specific effects. We also examine the difference in cis-regulatory variation
of genes across different levels of sex bias in gonads and heads. Consistent with the idea that intersex correlations constrain expression
and can lead to sexual antagonism, we find more cis variation in unbiased and moderately biased genes in heads. In ovaries, reduced cis
variation is observed for male-biased genes, suggesting that cis variants acting on these genes in males do not lead to changes in ovary
expression. Finally, we examine the dominance patterns of gene expression and find that sex- and tissue-specific patterns of inheritance
as well as trans-regulatory variation are highly variable across biological crosses, although these were performed in highly controlled
experimental conditions. This highlights the importance of using various genetic backgrounds to infer generalizable patterns.},
  author       = {Puixeu Sala, Gemma and Macon, Ariana and Vicoso, Beatriz},
  issn         = {2160-1836},
  journal      = {G3: Genes, Genomes, Genetics},
  keywords     = {Genetics (clinical), Genetics, Molecular Biology},
  number       = {8},
  publisher    = {Oxford University Press},
  title        = {{Sex-specific estimation of cis and trans regulation of gene expression in heads and gonads of Drosophila melanogaster}},
  doi          = {10.1093/g3journal/jkad121},
  volume       = {13},
  year         = {2023},
}