Memorial review honors cytogeneticist Ninel A. Petrova and her dipteran chromosome research

Dr. Sc. Ninel A. Petrova, a cytogeneticist whose work helped establish the use of polytene chromosomes in the systematics and evolution of dipteran insects, died on 18 April 2024 at the age of 84. A memorial review describes nearly 60 years of research at the Zoological Institute of the Russian Academy of Sciences in Leningrad, now St. Petersburg, focusing on black flies (Simuliidae) and non-biting midges (Chironomidae).

Petrova was born on 28 March 1940 in Petrodvorets near Leningrad, now Peterhof in St. Petersburg. During the Great Patriotic War, she and her mother were evacuated from besieged Leningrad to Pronsk in Ryazan Province. After returning to Leningrad, she completed school in 1957 and later studied plant genetics, particularly rye, at Leningrad State University under Prof. Vasily S. Fedorov. Following her diploma work, she joined the Zoological Institute as a research assistant in the newly established Laboratory of Karyosystematics and Population Genetics and remained there for almost her entire working career.

Working first under Prof. Lidia A. Chubareva, Petrova developed a research program in the comparative cytogenetics of black flies. The memorial account credits her publications with demonstrating that rearrangements in giant polytene chromosomes can help address systematics and phylogeny at several taxonomic levels, including the separation of closely related species and the assessment of relationships among higher taxa. Her studies frequently combined karyological and morphological evidence for genera including Cnephia, Helodon, Schoenbaueria and Austrosimulium. She defended her Candidate (Ph. D.) dissertation in 1975 on the comparative karyology of blood-sucking black flies in the genera Cnephia, Metacnephia and Sulcicnephia.

In the late 1970s, Petrova expanded her karyotaxonomic work to Chironomidae while continuing to study Simuliidae. She examined chromosome morphology across different phylogenetic lineages and subfamilies and produced original chromosome maps for chironomid species from five subfamilies. Her research considered geographic and seasonal variation in chromosome band structure and incorporated material collected in multiple Russian regions and in Mongolia, Lithuania, Italy, Bulgaria, Belarus and Ukraine. These studies were based on insect specimens and chromosome analysis rather than a new controlled experiment in the memorial review.

Petrova and Chubareva’s 2008 atlas summarized black fly karyotypes through cytophotomaps of polytene chromosomes from 124 species in 32 genera in Russia and neighboring countries. It also included descriptions and drawings of taxonomically significant morphological characters. Her final monograph, published with former doctoral student Sergey V. Zhirov in 2022, reviewed polytene chromosomes and larval morphology in five chironomid subfamilies. Drawing largely on the authors’ original material, the book included chromosome microphotographs and comparative information on chromosome morphology and polymorphism across populations and species.

Petrova also participated in animal and cell-level research on environmental pollutants. In collaboration with Bulgarian and Italian colleagues, she examined how heavy metals affected the structure and function of polytene chromosomes in model chironomid species through laboratory experiments and field comparisons. The associated work reported heritable and somatic chromosomal rearrangements and genotoxic effects for some metal ions. The memorial review states that the chironomid genome responded more strongly to toxicants than the external morphology of the larvae; this was an observation from insect studies, not evidence of human clinical effects. Her work in this area included participation in NATO projects on heavy-metal-induced genome instability and pollution of water resources.

After the Chernobyl nuclear accident on 26 April 1986, Petrova went to the affected region and collected chironomids to investigate radiation-associated changes in the structure and function of their polytene chromosomes. Subsequent publications examined chromosomal variability in chironomids from the Chernobyl zone. For this work, she received the Russian state medal “For the Rescue of the Perished” in 2006 under a presidential decree recognizing active participants in the response to the accident.

By integrating chromosomal and morphological analyses, Petrova helped describe five new species and two genera of Simuliidae. She also contributed to the international description of the chironomid Polypedilum pembai from Malawi, whose distinctiveness was initially inferred from chromosomal data. The memorial account records approximately 200 scientific articles, three monographs and a chapter in a collective monograph. The chironomid genus Ninelia and the black fly species Sulcicnephia petrovae were named in her honor, and all of the taxonomic names listed in the memorial are described as currently valid.

This memorial review is an account of Petrova’s publications, career history, taxonomic contributions and scientific service rather than a new empirical study. It credits her with training younger researchers, lecturing in Turin and Milan, presenting at national and international meetings, and serving for 25 years as scientific secretary of a specialist council that reviewed candidate and doctoral dissertations in entomology and parasitology. The account presents her long association with the Zoological Institute and her extensive comparative work on dipteran chromosomes as her principal scientific legacy.

Subject of Research: Memorial review of Ninel A. Petrova’s cytogenetic and karyotaxonomic research on non-biting midges and black flies

Article Title: In Memoriam: Cytogeneticist Dr. Sc. Ninel A. Petrova (1940–2024) — life and scientific heritage

Article References: Kuznetsova, V., Michailova, P., Przhiboro, A., & Khabazova, N. (2024). In Memoriam: Cytogeneticist Dr. Sc. Ninel A. Petrova (1940–2024) — life and scientific heritage. Comparative Cytogenetics, 18, 277-305. https://doi.org/10.3897/compcytogen.18.138747

Image Credits: AI Generated

DOI: 10.3897/compcytogen.18.138747

Keywords: Ninel Petrova, cytogenetics, karyotaxonomy, polytene chromosomes, Chironomidae, Simuliidae, Diptera, environmental pollution, taxonomy, scientific legacy, Memoriam, Cytogeneticist