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WonderCell biology biography

American biologist Ernest Everett Just showed that an egg cell's surface changes rapidly at fertilisation and helps stop extra sperm from getting in. Working with sea urchins and other marine animals, he insisted that cells be studied in conditions as close to natural as possible.

Ernest Everett Just

BiographyBiologyScienceOcean

The story behind the card

Just taught at Howard University in Washington from 1907 until his death and spent some twenty summers at the Marine Biological Laboratory in Woods Hole, Massachusetts, where his careful handling of marine eggs made him a sought-after expert. He described what is now called the fast block to polyspermy, the rapid change that keeps a second sperm out of the egg. In 1915 he became the first person to receive the Spingarn Medal from the US civil rights organisation NAACP. Racism kept him out of posts at major American research universities, so from 1929 he worked more and more in Europe: at the Stazione Zoologica in Naples, the Kaiser Wilhelm Institute in Berlin and later Roscoff in France. His 1939 book The Biology of the Cell Surface argued that the cell's outer layer, not only the nucleus, drives development. He died in 1941.

Türkçe oku
Amerikalı biyolog Ernest Everett Just, döllenme anında yumurta hücresinin yüzeyinin hızla değiştiğini ve fazladan spermin girmesini engellemeye yardım ettiğini gösterdi. Deniz kestaneleri gibi deniz canlılarıyla çalışan Just, hücrelerin doğal ortamlarına olabildiğince yakın koşullarda incelenmesi gerektiğini savundu.

Just, 1907'den ölümüne dek Washington'daki Howard Üniversitesi'nde ders verdi; yaklaşık yirmi yaz boyunca Massachusetts'teki Woods Hole Deniz Biyolojisi Laboratuvarı'nda çalıştı. Deniz canlılarının yumurtalarıyla çalışırken gösterdiği titizlik onu aranan bir uzman yaptı. Bugün “polispermiye karşı hızlı engel” denen olayı, yani ikinci bir spermin yumurtaya girmesini önleyen ani değişimi o tanımladı. 1915'te ABD'deki sivil haklar örgütü NAACP'nin verdiği Spingarn Madalyası'nın ilk sahibi oldu. Irkçılık yüzünden ABD'nin büyük araştırma üniversitelerinde kadro bulamayınca 1929'dan itibaren giderek daha çok Avrupa'da çalıştı: Napoli'deki Stazione Zoologica'da, Berlin'deki Kaiser Wilhelm Enstitüsü'nde, daha sonra da Fransa'da Roscoff'ta. 1939'da yayımlanan The Biology of the Cell Surface (Hücre Yüzeyinin Biyolojisi) adlı kitabında, gelişimi yalnızca çekirdeğin değil hücrenin dış katmanının da yönlendirdiğini savundu. 1941'de öldü.

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Background reading: Ernest Everett Just
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