Mitotic and meiotic analysis of B chromosomes in Prochilodus lineatus from Mogi-Guaçu river

Abstract

The species Prochilodus lineatus, popularly known as Curimbatá is widely distributed in the Neotropics, especially in the upper basin of the Parana River. Cytogenetic studies in this species showed a diploid number of 54 chromosomes, metacentric, and submetacentric types, containing a range of zero to nine B chromosomes. These extra chromosomes are characterized by being heterochromatic, which normally do not show homology with the chromosomes of the complement A, and have a different frequency, size, and morphology. In P. lineatus polymorphism was found in the microchromosomes B, which may occur as acrocentric, metacentric, and submetacentric. In addition, there are currently few studies focused on the meiotic behavior of B chromosomes in fish, which makes it extremely important to conduct studies on the meiotic segregation of additional elements on fish populations carriers. The present study aims to analyze the mitotic and meiotic behavior of B microchromosomes found in P. lineatus, from the Mogi-Guaçu (Pirassununga, SP). These data will contribute to a better understanding of the segregation of these elements in genomics during the formation of genetic cells, which can cause variations in the frequency and pattern of the transmission of these microchromosomes.(AU)