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. MEIOSIS is the specialized cell division required in all eukaryotes with a sexual life cycle to produce gametes with a haploid content of chromosomes. During meiosis one round of DNA replication is associated with two rounds of chromosome segregation. The general progression of meiosis is conserved evolutionarily, and hence meiotic prophase and chromosome segregation are similar in plants, animals, and fungi. Following S phase, at leptotene, chromosomes condense and the two sister chromatids are held together along their length by the sister-chromatid cohesin complexes that help to form the axial element that runs the length of the leptotene chromosome. The double-strand breaks that initiate homologous recombination usually occur at this stage. At the leptotene-zygotene transition there is a transient remodeling of chromosome architecture that can include the attachment and clustering of telomeres on the nuclear envelope. These events facilitate the pairing of homologous chromosomes. Coincident with pairing, the homologs zip up-i.e., synapse-as a tripartite synaptonemal complex (SC) forms along the length of the two chromosomes between their axial elements. At pachytene, the homologs are completely synapsed and homologous recombination is completed, leading to crossing over between homologs and chiasmata formation. During diplotene and diakinesis, the SCs fall apart as chromosomes condense further. The homologs are held together by the chiasmata until they segregate away from each other at the first meiotic division (MI). During the subsequent second meiotic division (MII), sister chromatids separate from each other to ...

Mapping of QTL for kernel abortion caused by in vivo haploid induction in maize (Zea mays L.)

“…The ameiotic1 (am1) gene is a candidate for P1 qEnA-5c and P1 qTA-5c, located between phi109188 and bnlg1879 on chromosome 5. Cande and Freeling [46] found that this mutant plays an important role in establishing the meiotic cell cycle. ZmSRS1-2 (GRMZM2G414043) is a candidate gene for P2 qEnA2 nd -7.…”

Untitled

“…Большинство из этих мутаций и генов были открыты Инной Голубовской в ходе ее замечательной карьеры цитогенетика». И далее: «Помимо общего цитологического исследования для классификации мутантных фенотипов, Голубовская сосредоточила усилия на изучении нескольких ключевых регуляторных мутаций …» (Cande, Freeling, 2011). Эти цитаты, как и сам факт публикации статьи в авторитетном журнале Генетического общества Америки -свидетельства выдающегося вклада Голубовской в изучение генетических механизмов мейоза и цитологического проявления действия генов мейоза.…”

“…К концу 80-х годов достижения И. Н. Голубовской заслужили международное признание. Биографы И. Н. Голубовской З. Канди и М. Фриллинг квалифицировали ее как ученого, получившего в мировом сообществе генетиков репутацию «лучшего генетика кукурузы в СССР» (Cande, Freeling, 2011). Несмотря на то, что эти американские авторы вряд ли знали все работы по генетике кукурузы, проводившиеся в СССР, характеристика, данная ими И. Н. Голубовской, вероятно, справедлива для 1970-1980 гг.…”

“…В период бурного развития молекулярной и клеточной биологии, генетики прокариот и одноклеточных эукариот работы Голубовской привлекли внимание молекулярных генетиков к мейозу у цветковых растений. По мнению тех же американских авторов (Cande, Freeling, 2011) (Golubovskaya, 1989). В чем состояла эта концепция?…”

Identification and Map-Based Cloning of the Light-Induced Lesion Mimic Mutant 1 (LIL1) Gene in Rice

“…These lesions, which can resemble either disease symptoms or pathogen-inducible HR, frequently are associated with enhanced plant disease resistance to a wide range of pathogens ( Lorrain et al, 2003 ). Numerous LMMs have been identified in many plants, including Arabidopsis ( Dietrich et al, 1994 ; Bowling et al, 1997 ; Mou et al, 2000 ), maize ( Walbot, 1991 ; Johal et al, 1995 ), wheat ( Yao et al, 2009 ; Du et al, 2014 ; Wang et al, 2016 ), barley ( Wolter et al, 1993 ; Rostoks et al, 2006 ) and rice ( Takahashi et al, 1999 ; Yin et al, 2000 ; Mizobuchi et al, 2002 ; Campbell and Ponald, 2005 ; Mori et al, 2007 ; Wu et al, 2008 ; Qiao et al, 2010 ; Chen et al, 2012 ; Fekih et al, 2015 ; Li et al, 2016 ). The notion that complex and diverse pathways underlie the phenotypes of LMMs is supported by the mutated genes falling into many different functional groups, including membrane-associated proteins ( Büschges et al, 1997 ; Lorrain et al, 2004 ; Noutoshi et al, 2006 ), ion channel proteins ( Balague et al, 2003 ; Rostoks et al, 2006 ), an U-Box/Armadillo repeat protein ( Zeng et al, 2004 ), a splicing factor 3b subunit 3 ( Chen et al, 2012 ), a zinc-finger protein ( Dietrich et al, 1997 ), a heat stress transcription factor ( Yamanouchi et al, 2002 ), a clathrin-associated adaptor protein ( Qiao et al, 2010 ) and proteins involved in the biosynthesis and metabolic pathways of phenolic compounds ( Gray et al, 1997 ), such as porphyrin ( Hu et al, 1998 ; Ishikawa et al, 2001 ) and fatty acids or lipids ( Kachroo et al, 2001 ; Brodersen et al, 2002 ).…”