Inna Golubovskaya: the life of a geneticist studying meiosis

Abstract

Maize, with its excellent forward genetics and male sterility screens, was used to identify >50 meiotic mutants representing at least 35 genes that affect key prophase processes such as pairing, synapsis, and homologous recombination. Most of these mutants were found by Inna Golubovskaya during the course of her remarkable career as a cytogeneticist. In addition to undertaking general cytological surveys to classify mutant phenotypes, Golubovskaya focused her efforts on characterizing several key regulatory mutants: ameiotic1 (am1), required to establish the meiotic cell cycle in maize; absence of first division (afd1), required for proper prophase chromosome morphology and for meiotic sister-chromatid cohesion leading to a reductive chromosome segregation at the first meiotic division; and plural abnormalities of meiosis (pam1), required for the clustering of telomeres on the nuclear envelope needed for pairing and synapsis. Her dramatic childhood in Leningrad during its siege in World War II, her fortuitous education in genetics at Leningrad State University, her continued research at the forward-looking Institute of Cytology and Genetics of the USSR Academy of Science Siberian branch, her plight at the fall of the Soviet Union, and her work in America helped engender a unique and valuable plant geneticist. Inna Golubovskaya related this personal history to the authors in conversation.

Figure 1.—

Inna Golubovskya, 2010, Berkeley, California.

Figure 2.—

“She was my goodness,” said Inna of Barbara McClintock (left) at Cold Spring Harbor, New York, in 1991. Inna learned plant cytogenetics at Leningrad State University from Burnham's Discussions in Cytogenetics (Burnham 1962) and a collection of McClintock's papers.

Figure 3.—

A mtm00-10 mutant with defects in pairing and centromere orientation at metaphase I of meiosis. Shown is an image of anaphase 1 in maize mtm00-10 mutant meiocyte, stained for Cent C (a red centromere probe) and for 5S rDNA (a green probe), and DAPI-stained chromosomes (blue). The Cent C repeat FISH probe marks all centromeres; however, the 5S rDNA FISH probe marks only the chromosome 2 long arm, where the 5S ribosomal DNA locus is located. The mtm00-10 gene affects chromosome segregation at anaphase 1. Homologous chromosomes that pair properly during prophase 1 segregate regularly to opposite poles at anaphase 1 (arrows). However, some homologous chromosomes remain unpaired, and they line up at the middle of cell. The sister centromeres are oriented toward opposite spindle poles; however, sister-chromatid cohesion is not released at centromeric regions, and the chromosomes do not move poleward (arrowheads). In this nucleus, the homologs of chromosome 2 (green signals) did not pair and remain in the middle of the cell.