# Tatiana Dettlaff

Tatiana Antonovna Dettlaff (Russian: Татьяна Антоновна Детлаф; 1912–2006) was a Russian developmental biologist known for her pioneering research on oocyte growth and maturation in sturgeons, a group of ancient fish species facing significant conservation challenges. A key aspect of her work involved developing methods for the artificial propagation of sturgeons through hormonal induction of spawning, controlled fertilisation, and embryo rearing.
Dettlaff was Professor Emeritus of the Kol'tsov Institute Developmental Biology, Russian Academy of Sciences, where she headed the Filatov Laboratory of Experimental Embryology for more than 20 years and served as the Editor-in-Chief of ontogenez (Russian Journal of Developmental Biology). She was an honorary member of the Russian Academy of Natural Sciences, and a member of the International Society of Developmental Biologists. Dettlaff was the recipient of Kowalevsky Prize, the most important scientific award in Russia in the field of developmental biology.

## Early life and education

Dettlaff was born in Moscow to Sofia Aronovna and Anton Iosifovich. Her mother was a physician, and her father was a teacher who headed the pedagogical and agricultural training colleges in Volokolamsk from 1918 to 1929.
After graduating from a seven-year school and completing two courses of training college, Dettlaff appeared and passed the entrance exams for the biology department of the 2nd Moscow Pedagogical Institute in 1925. However, she did not secure admission as a few slots were reserved for the children of employees. Instead, she enrolled in the Simferopol Pedagogical Institute. A few months later, Dettlaff transferred to the 1st Moscow State University after the biological faculty announced additional admission spots. She joined the Department of Developmental Dynamics under Prof. Mikhail Zavadovsky, a Russian and Soviet biologist specialising in the reproductive biology of livestock.
During her third year, while at the Zvengorod Biological Station, Dettlaff attended a practical course in microsurgery in developmental mechanics conducted by Prof. Dmitrii P. Filatov, an eminent scientist and embryologist. Although she was interested in the field of developmental mechanics, Dettlaff did not follow Prof. Filatov for her diploma work as she dreamed of working in phenogenetics. In response, Filatov invited her to the Institute of Experimental Biology and introduced her to the director Prof. Nikolai K. Kol’tsov, who proposed she work on a project on Morphology of embryonic lethaIs in Drosophila. He accompanied Dettlaff as a technician to the Institute where she was tasked with looking after axolotls who regularly became ill and died. Over the next two months, she struggled to obtain, fix, embed and cut eggs, but Filatov continued to be an encouraging presence. During this time, Dettlaff became interested in the specific structural features of the ectoderm in Anura, which had been sidelined by embryologists. After graduating from the university in 1933, Filatov proposed she join postgraduate school under his guidance; Dettlaff agreed much to the dismay of Prof. Kol’tsov who did not forgive this decision until he died.
In 1937, she defended her candidate (PhD) thesis on Development of the Nervous System in Anura with Special Reference to Organizer Action.

## Career

After graduating, Detlaff briefly worked in the embryological laboratory of Prof. Alexei Alexeivich Zavarzin, who was best known for his research on the evolutionary and comparative aspects of histology. He had moved from Leningrad to Moscow with his department and wanted Prof. Filatov to head the Laboratory of Experimental Embryology at All-Union Institute Experimental Medicine. Unfortunately, the laboratory shuttered within a year, and Detlaff transferred to the Institute of Evolutionary Morphology, USSR Academy of Sciences in 1939 after Prof. Ivan Schmalhausen hired her as a supemumerary research worker.
During the Second World War, Detlaff evacuated from Moscow to Chuvashia and then Kazakhstan, where she worked at the Laboratory of Developmental Dynamics run by Prof. Mikhail Zavadovsky at the Kazakh branch of the USSR Academy of Sciences. Here, she studied multiple pregnancy of sheep, visiting state and collective farms to introduce shepherds and zoo technicians to Zavadovsky's method of obtaining polycarpous farm animals in sheep husbandry. After returning to Moscow in 1943, she started working on her doctoral thesis under the guidance of Prof. Schmalhausen. The first volume of her thesis Structure and Properties of Ectoderm, Chordamesoderm, and their Derivatives in Different Species of Anamnia explored the history of the theory of germ layers.