[Massive gene losses: the case of chemoreceptors in aquatic tetrapods].

The existence of multigene families is the result of gene duplication. In vertebrates, the genes coding for the chemoreceptors involved in olfaction often form large families, sometimes comprising several thousand genes. In this case, it is assumed that a large number of genes is essential to discriminate between a large number of odorant molecules, and that the ability to identify a large number of odors may be necessary for different purposes, such as finding food and sexual partners, and avoiding predators.

The nature and distribution of putative non-functional alleles suggest only two independent events at the origins of Astyanax mexicanus cavefish populations.

Background: Several studies suggested that cavefish populations of Astyanax mexicanus settled during the Late Pleistocene. This implies that the cavefish's most conspicuous phenotypic changes, blindness and depigmentation, and more cryptic characters important for cave life, evolved rapidly.

Results: Using the published genomes of 47 Astyanax cavefish from la Cueva de El Pachón, El Sótano de la Tinaja, La Cueva Chica and El Sótano de Molino, we searched for putative loss-of-function mutations in previously defined sets of genes, i.

Diversity and evolution of the vertebrate chemoreceptor gene repertoire.

Chemoreception - the ability to smell and taste - is an essential sensory modality of most animals. The number and type of chemical stimuli that animals can perceive depends primarily on the diversity of chemoreceptors they possess and express. In vertebrates, six families of G protein-coupled receptors form the core of their chemosensory system, the olfactory/pheromone receptor gene families OR, TAAR, V1R and V2R, and the taste receptors T1R and T2R.

Acoustic signatures in Mexican cavefish populations inhabiting different caves.

Complex patterns of acoustic communication exist throughout the animal kingdom, including underwater. The river-dwelling and the Pachón cave-adapted morphotypes of the fish Astyanax mexicanus are soniferous and share a repertoire of sounds. Their function and significance is mostly unknown.