PhD student position in Bar Ilan University, Israel: Drivers and reducers
of sexual conflict in utero

Sexual conflict can develop if alleles affect traits in both sexes in an
opposite manner, promoting fitness in one sex while decreasing fitness
in the opposite sex.Although mainly studied in adults, the processes
that give rise to sexual conflict likely start in utero, thus shaping
the organism's entire life trajectory. This fascinating process has
yet to be elucidated, with a key question remaining unresolved:What
factors during fetal development underly sexual conflict?Here we seek
to answer this question by providing a mechanistic understanding of
sexual conflict during ontogeny, starting in gestation.  We will focus
on the hypothalamic-pituitary-gonadal (HPG) axis and its components,
such as testosterone (T). This axis exhibits sex differences in
optimal levels and in the mediation of morphological, physiological,
and behavioral processes throughout life, paving the way for sexual
conflict. Sexual conflict may be affected by environmental factors,
such as steroid transfer between fetuses in litter-bearing mammals. It
may also involve a genetic component. In the case of the HPG axis, if
its components are heritable, then sex different genetic architecture
(from mother only to daughter and father only to son) may reduce sexual
conflict.  We here propose a holistic approach to testing the contribution
of the environmental and genetic effects and their interactions to sex
differences in the HPG axis before birth. Our preliminary results on
T show sex differences that may be indeed compensated by sex different
genetic architecture, which may serve to reduce sexual conflict.

Our in utero study will take advantage of the annual culling of hundreds
of free-ranging invasive nutrias (Myocastor coypus) in Agmon Hula Park,
Israel, which will afford us access to many large litters with validated
maternity and widespread within-litter multiple paternity. It will
further offer a unique opportunity to test a complete, large, natural
dataset that includes variability beyond that of model laboratory
animals.We will integrate data collected from different tissues and
in different developmental stages, including circulating T in fetal and
maternal hair, T in amniotic fluid, and gene expression levels of HPG axis
components in fetal gonads and brain areas involved in sexual dimorphism in
quantitative morphological and behavioral traits. Then, we will evaluate
the contribution of environmental vs. genetic effects,assess sexual
conflict using quantitative genetics tools, and test whether there is a
differential genetic architecture within and between sexes, in different
developmental stages. We will also map the expression of HPG axis genes
at different developmental stages (trimesters) and in specific tissues and
determine whether there is a relationship between levels of HPG axis gene
expression.The interaction between the environmental and genetic effects
will be explored in a unified statistical model that will partition the
variance of sex differences that can account for sexual conflict.This
naturally controlled experiment, where the environment is contained
within the mother, is expected to yield a clearer understanding of the
environmental-heredity interplay driving sexual conflict.Understanding
the contribution of environmental vs. genetic effects on sex differences
in HPG axis components is expected to shed light on the mechanisms behind
sexual dimorphism in other fitness-related traits.

This four year position includes tuition, a full scholarship, salaried
teaching opportunities, and conference travel funds.

We are looking for a bright, highly motivated scholar who has completed an
MSc in the fields of Zoology, Ecology, Behavioural Ecology, Endocrinology,
and/or Computational biology. An experience in field work, dissections,
molecular techniques, and computational skills are an asset. Interested
candidate should send a CV and a statement of interests, in addition to
proof of MSc or transcripts to Dr. Lee Koren (lee.koren@biu.ac.il).

Lee Koren <Lee.Koren@biu.ac.il>

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