Spindle irregularities, chromatin transfer, and chromatin stickiness during male meiosis in Anemone tetrasepala (Ranunculaceae)

Authors: PAWAN KUMAR RANA, PUNEET KUMAR, VIJAY KUMAR SINGHAL

Abstract: Detailed cytological investigations performed in Anemone tetrasepala Royle from the Pangi Valley revealed the presence of various irregularities (spindle irregularities, chromatin transfer, chromatin stickiness, and nonsynchronous condensation of chromatin material) for the first time in the species that existed at diploid level (2n = 14). Spindle irregularities resulted in dyads, triads, polyads, and micronuclei in sporads during microsporogenesis and variable sized pollen grains and reduced fertility in pollen grains (85.38%). Direct fusion among proximate meiocytes resulted in the formation of syncyte pollen mother cells. Such syncytes yielded jumbo-sized pollen grains that were surely of unreduced nature in their genetic constitution. Due to severe chromosome stickiness, chromosome separation during anaphases was also affected. Another interesting observation was the nonsynchronous condensation of 1-2 chromosomes during anaphase-I. This paper discusses the consequences of chromosomal and spindle irregularities on the course of meiosis and microsporogenesis and ultimately on the end products.

Keywords: Anemone tetrasepala, nonsynchronous condensation, intra-microsporal, jumbo pollen grains, meiotic course, Pangi Valley, syncytes

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