Searching for mechanisms behind meiotic abnormalities in Crotalaria spectabilis Roth

Abstract

ABSTRACT The identification of epigenetic marks associated with problems in the meiotic process can enlighten the mechanisms underlying the irregularities and the impacts in the genetic constitution of gametes. Therefore, this study aimed to verify the relationship between the pattern of phosphorylation in serine 10 of histone H3 (H3S10ph), a (peri) centromeric epigenetic mark, with meiotic abnormalities in a wild population of Crotalaria spectabilis Roth. The main abnormalities observed were transfer of genetic material through cytoplasmatic connections, DNA elimination and abnormal spindle array. Different forms of elimination (chromatin fragmentation, ring formation, lagging chromosomes and micronuclei) were observed from the early phases until tetrad formation. The eliminated chromatin was either positive or negative for the immunosignal of H3S10ph, so it may be occurring elimination of acentric fragments, as well as of chromosomes with active or inactive centromeres. Therefore, dysfunctional centromere is not the only candidate cause for elimination. The transfer of genetic material and the abnormal spindle arrays are evidence that this population can produce aneuploid gametes and 2n pollen grains.

Keywords

• Leguminosae
• cytomixis
• abnormal meiotic spindle
• unreduced pollen grain
• chromosome elimination