Identificação de herdabilidade de coloração em lebiste (poecilia reticulata) (Peters 1859)

Abstract

The development of new genetic improvement techniques to determine the genotype and phenotype of the lebiste is an important aspect for the development of aquarofilia, since this procedure makes it possible to select the most attractive characteristics of the species for the ornamentation market. For this reason, the proposal of the work was to analyze the heritability processes regarding the coloring pattern between wild and albino specimens. The results showed that the staining pattern in wild individuals varies according to the presence or absence of light. The irradiated melanophores distributed by the body of the wild lebister, usually in the presence of light for a period of 10 minutes, retract the melanin granules towards the center of the cell manifesting externally as absence of color. The pigments found in the xanthophores were carotenoids, with orange, red, and yellow highlights. The albinos that correspond to non-wild specimens presented the melanophores and melanin in low quantity, so they could be classified as albinos or pseudoalbinos. Albinism appeared in lebens in individuals where the male presented a characteristic of heterozygosis, and its crossbreeding generated offspring with individuals with albino and wild phenotype, where there is a probability that 50% of the individuals are normal offspring not carrying the gene and 50% probability of the heterozygous offspring carry the gene. The results obtained in the crosses of group 2 (wild x wild) and group 3 (albino x wild), indicated that the pattern of inheritance was of the complete type, that is, the wild ones prevailed. However, in groups 1 (albino x albino) and 4 (wild x albino) expression of the two described phenotypes occurred. At the cross-over, between pure wild and mutant (albino) strains, the wild-type allele was dominant over the albino recessive allele. The inheritance pattern of albinism is probably a characteristic of a recessive mutant allele and the wild-type is a dominant allele. Crosses between lineages proved to be a viable technique to select features required for ornamentation between the wild and albino pattern.