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Os textos são da exclusiva responsabilidade dos autores
All texts are of the exclusive responsibility of the authors
HOW DO WE CHOOSE A PARTNER? NEURAL CIRCUITS INVOLVED IN
INBREEDING AVOIDANCE AND MATE SELECTION
Susana Q. Lima
Champalimaud Neuroscience Programme at Instituto Gulbenkian de Ciência, Oeiras
Grant nº 176/08
Abstract:
I have proposed to investigate the neuronal mechanisms underlying inbreeding
avoidance (IA). IA is crucial for species survival, since only by mating with those who
do not share our own genetic makeup we can avoid passing on recessive genetic
disorders to our progeny. The ability to select sexual partners who are genetically
dissimilar calls for prospective mates to display signs that reveal their genetic identity in
a way that can be read by choosers. Then choosers must be able to compare their own
genetic identity to that of the prospective mate and form a decision taking into account
the distance between the two. The value of "attractiveness" of a prospective mate, and
likelihood of mating, should decrease as the individual becomes too genetically similar
to oneself. In neurobiological terms, one can hypothesize that cues indicating genetic
identity are first transduced by sensory systems and translated into electrical signals that
the chooser can use to make the decision.
The first step was to establish a mate choice behavioral paradigm using two strains
(PWD and PWK) of inbred wild derived mice, Mus musculus musculus. These two
strains are derived from animals caught independently from the same population and so
are genetically different. The hypothesis is the following: if females of one of the strains
(for example PWD) are doing IA, then they should prefer to mate with males from the
other strain.
To investigate which males PWD females prefer we developed a behavioral paradigm
based on a Y-maze apparatus where a single female can choose between two males of
the different strains. In this apparatus the female is free to move and choose which male
she prefers to spend time with (measured by time spent in the proximity of each male);
the apparatus allows nose-nose contact through a perforated wall- this impedes full
contact, but still permits investigation of non-volatile chemicals, like pheromones,
which are involved in sexual behavior.
Preliminary data suggests that female PWD prefer to stay near a male PWK when
compared to a male of her own strain. This is, they seem to be doing IA. Future
experiments include tests in different behavioral apparatus. The Y maze only allows to
measure time spent together, which some other groups have used as a proxy for mate
preference. However, to ensure that this is an actual mate preference, our next
experiments include partner-preference tests, where females are allowed to directly
interact with tethered males.