ABSTRACT
Y chromosomes typically harbour a small number of genes and an abundance of repetitive sequences. In Drosophila, the Y chromosome comprises multimegabase long segments of repetitive DNA and a handful of protein-coding genes. In mammals, the Y chromosome also harbours a disproportionally high abundance of repeats. Here, we built on a Drosophila melanogaster model in which the Y chromosome is decoupled from sexual determination. Genotypes were genetically identical for the autosomes, X chromosome, and mitochondria, but differ by the presence or dose of the Y chromosome. Addition of an extra Y chromosome had limited impact in males. However, the presence of a Y chromosome in females induced a disproportionate response in genes expressed in the ovaries as well as genes encoded by the mitochondrial genome. Furthermore, the data revealed significant consequences of Y chromosome presence in larvae neuronal tissue. This included the repression of genes implicated in reproductive behaviour, courtship, mating and synaptic function. Our findings exhibit the Y chromosome as a hotspot for sex-specific adaptation. They suggest roles for natural selection on Y-linked genetic elements exerting impact on sex-specific tissues as well as somatic tissues shared by males and females.
Subject(s)
Drosophila melanogaster/genetics , Neurons/physiology , Sexual Behavior, Animal , Y Chromosome/genetics , Animals , Drosophila melanogaster/growth & development , Female , Genotype , Larva/genetics , Larva/growth & development , Male , Sex Determination ProcessesABSTRACT
In the present study we compare genetic characteristics (allele diversity and observed heterozygosity) of microsatellite loci, from three stingless bee species (Plebeia remota Holmberg, Partamona mulata Moure In Camargo and Partamona helleri Friese), amplified by using heterospecific primers originally designed for Melipona bicolor Lepeletier and Scaptotrigona postica Latreille. We analyzed 360 individuals of P. remota from 72 nests, 58 individuals of R. mulata from 58 nests, and 47 individuals of P. helleri from 47 nests. The three species studied showed low level of polymorphism for the loci amplified with primers derived from M. bicolor. However, for the loci amplified with primers derived from S. postica, only P. remota presented low level of polymorphism.
Subject(s)
Bees/classification , Bees/genetics , Alleles , Animals , Heterozygote , Microsatellite RepeatsABSTRACT
In the present study we compare genetic characteristics (allele diversity and observed heterozygosity) of microsatellite loci, from three stingless bee species (Plebeia remota Holmberg, Partamona mulata Moure In Camargo and Partamona helleri Friese), amplified by using heterospecific primers originally designed for Melipona bicolor Lepeletier and Scaptotrigona postica Latreille. We analyzed 360 individuals of P. remota from 72 nests, 58 individuals of P. mulata from 58 nests, and 47 individuals of P. helleri from 47 nests. The three species studied showed low level of polymorphism for the loci amplified with primers derived from M. bicolor. However, for the loci amplified with primers derived from S. postica, only P. remota presented low level of polymorphism.
No presente trabalho compararam-se as características de locos de microssatélite, como diversidade alélica e taxa de heterozigose observada, de três espécies de abelhas sem ferrão (Plebeia remota Holmberg, Partamona mulata Moure In Camargo e Partamona helleri Friese), amplificados com oligonucleotídeos heteroespecíficos originalmente desenhados para Melipona bicolor Lepeletier e Scaptotrigona postica Latreille. Foram analisados 360 indivíduos de P. remota de 72 ninhos, 58 indivíduos de P. mulata de 58 ninhos e 47 indivíduos de P. helleri de 47 ninhos. As três espécies apresentaram baixo nível de polimorfismo para locos amplificados com oligonucleotídeos derivados de Melipona bicolor. Entretanto, para os locos amplificados com oligonucleotídeos derivados de S. postica, somente P. remota apresentou baixo nível de polimorfismo.
