Tatiana Detlaf

Tatiana Antonovna Dettlaff (Russian: Татьяна Антоновна Детлаф; 1912–2006

Early life and education Dettlaff was born in Malakhovka, Moscow to Sofia Aronovna and Anton Losifovich. 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 second Moscow Pedagogical Institute in 1925. However, she failed to secure admission as a few slots were reserved for the children of employees. She enrolled in the Simferopol Pedagogical Institute instead, and a few months later, transferred to the first Moscow State University after the biological faculty announced additional admission spots. She joined the Department of Developmental Dynamics under Mikhail Zavadovsky, a Russian and Soviet biologist specialising in the reproductive biology of livestock. The laboratories of Schmalhausen and Dragomirov, where she worked, were closed.

The rise of Lysenkoism resulted in the persecution of around 3,000 biologists, and Dettlaff believed her "dismissal was imminent." They were later joined by biologist Alexander Zotin. Their study initiated a widespread trend of developmental biology studies focusing on the morphology and physiology of the sturgeon fish, oocyte maturation, and the relative criteria of biological time. Dettlaff recalls that while artificial breeding of sturgeon fish was important, many researchers at the time, including embryologists, cytologists, morphologists, ichthyologists, biochemists, and molecular biologists, became more involved in the field because they were forced to consider alternative study streams after Lysenko's campaign against genetic research. In a 1997 interview, Dettlaff said that oocyte maturation, and embryonic and prelarval development in the sturgeon fish now compared, based on the degree of available knowledge, with the development of amphibians and even exceeded it in some aspects. She believed that because oocytes and eggs of sturgeon were a "very convenient object of study," the knowledge will continue to expand. She also noted the growing international interest in the task of preservation and reproduction of sturgeon. Taking these observations into account, Dettlaff, along with her brother, physicist Andrei Dettlaff, proposed a method for relative characteristics of the duration of development. The results from this research were published in Experimental Species for Developmental Studies (1990) by a several authors, including Dettlaff and Sergei Georgievich Vassetzky, showing that "the shortest cell cycle during synchronous divisions of the nucleus in early development can be used as a time unit comparable in most poikilothermic animals and that the duration of various developmental periods and processes changes proportionally with temperature." The time unit was named “Detlaf” by biologist Alexander Neifakh, and was used in developmental biology studies to predict "the timing of different processes at different temperatures and elucidation of temporal patterns of development, including the genetic program of developmental time." At the time, this data had not been generalized and was not accessible to the wider community of biologists. Dettlaff noted that the existing literature contained discrepancies regarding the definition of these units and the methods regarding their determination. She felt necessary to maintain the recommendations of using this method, and to generalize the results from her studies to warn other researchers against the possible errors in application of the method. Her goal was to ensure that the measurable and comparable biological time becomes an integral part of research. In 1981, she was awarded the silver medal by VDNKh (Exhibition of Achievements of National Economy).

In 1994, Dettlaff became an honorary member of the Russian Academy of Natural Sciences. For several years, she was a member of the National Committee of Soviet Biologists, and rallied for Soviet scientists to attend international developmental biology conferences and congresses.

Death Dettlaff died on October 24, 2006. She was 94 years old.