Evelyn M. Witkin

**Evelyn M. Witkin** (née Maisel; Maris 9, 1921 - Yuli 8, 2023) ta kasance masanin kwayar cuta ta Amurka a Cold Spring Harbor Laboratory (1944-1955), SUNY Downstate Medical Center (1955-1971), da Jami'ar Rutgers (1971-1991). An dauki Witkin a matsayin mai kirkiro da wahayi a matsayin masanin kimiyya, malami da kuma mai ba da shawara.

Ayyukanta kan lalacewar DNA da Gyara DNA a cikin ƙwayoyin cuta shine tushe ga fahimtarmu game da irin waɗannan matakai a cikin kwayoyin halitta. Ayyukanta suna da aikace-aikace kai tsaye ga tasirin tsufa da kuma ganewar asali da maganin cututtukan mutane kamar ciwon daji. An ba Witkin lambar yabo ta Kimiyya ta Kasa a shekara ta 2002 saboda aikinta na farko a kan DNA mutagenesis da gyaran DNA. A cikin 2015, Witkin ta sami lambar yabo ta Albert Lasker don Binciken Kiwon Lafiya na asali "don abubuwan da aka gano game da martani na lalacewar DNA - wata muhimmiyar hanyar da ke kare genomes na dukkan halittu masu rai". 

## Ayyuka
Witkin ya girma ne a Queens, New York . Ta yi tafiya don halartar makarantar sakandare a Manhattan a Makarantar Sakandare ta Washington Irving, sannan makarantar 'yan mata, inda aka ƙarfafa ta ta bi sha'awarta ga kimiyya. Witkin ta sami digiri na farko daga Jami'ar New York a shekara ta 1941, tana karatun ilmin halitta. Ta yi niyyar kasancewa a can don aikin digiri, amma bayan da ta taimaka wajen shirya zanga-zangar adawa da manufofin makarantar na rashin baƙar fata su yi wasa a kwalejojin Kudancin, an dakatar da ita na watanni uku kuma an janye tayin samun digiri.   

Bayan ta sami digiri na farko, Witkin ta nemi Jami'ar Columbia inda ta sami digiri a shekara ta 1943.  Ta yi aikin Ph.D. tare da Theodosius Dobzhansky, wanda ya ba da shawarar ta ga Cold Spring Harbor Laboratory (CSHL). Witkin ta yi bazara a shekara ta 1944 a CSHL, inda ta koyi dabarun kwayoyin halitta don aiki tare da ƙwayoyin cuta, sabon filin bincike. A lokacin da ta zauna ta ware wani UV radiation-resistant mutant na *E. coli*; wannan shi ne karo na farko da aka ware maye gurbin da ke ba da UV radiation -resistance. Ta koma CSHL a 1945 kuma ta zauna a can don kammala bincikenta na PhD. An ba ta digiri a shekarar 1947.  

Bayan kammala karatunta ta yi aiki da Cibiyar Carnegie ta Washington don ci gaba da aiki a CSHL har zuwa 1955. Vannevar Bush, Shugaban Cibiyar Carnegie, ya shirya ta zo na ɗan lokaci bayan an haifi 'ya'yanta, wani tsari mai ban mamaki a wannan lokacin. Witkin ta yi amfani da lokutan aiki a cikin dakin gwaje-gwaje, kuma ta yi tsarawa, nazarin bayanai da rubutu a gida. A shekara ta 1949, Leo Szilard da Bernard Davis sun kusanci ta don shirya da kuma gyara Microbial Genetics Bulletin . Witkin ya shirya littafin daga 1950 zuwa 1964.

Daga 1955 zuwa 1971, Witkin ya yi aiki a Cibiyar Kiwon Lafiya ta Downstate ta Jami'ar Jihar New York a Brooklyn . [1] A shekara ta 1971 an nada Witkin Farfesa a fannin kimiyyar halittu a Kwalejin Douglass, Jami'ar Rutgers.[2][3] An ba ta suna Barbara McClintock Farfesa na Kwayoyin Halitta a 1979, kafin ta koma Cibiyar Waksman a Rutgers a matsayin Daraktan Laboratory a 1983. [4][5][6][7] Ta rike wannan mukamin har sai da ta yi ritaya a shekarar 1991, lokacin da ta zama farfesa a Rutgers.

## Bincike
Kafin a gano DNA a matsayin kayan gado, Witkin ya fara nazarin matsalolin tsakiya a cikin kwayoyin halitta wanda ya shafi kwafin kwayoyin halitta da hanyoyin da canje-canjen kwayoyin halitta ke yadawa. Lokacin da Witkin ta fara bincikenta, an ɗauka cewa wakilai kamar UV kai tsaye sun haifar da maye gurbi wanda ke da alhakin bunkasa juriya. Witkin da sauransu sun gano cewa ƙwayoyin cuta sun amsa ga lalacewar DNA ta hanyoyi da yawa. Ta hanyar waɗannan ayyukan kariya, ƙwayoyin cuta da kansu suna tsara canje-canjen kwayar halitta waɗanda suka faru a cikin martani ga lalacewar DNA.

A lokacin rani na farko a matsayin dalibi a Cold Spring Harbor, Witkin ta yi aiki tare da ƙwayoyin cuta, wanda aka gano kwanan nan yana da kwayoyin halitta kuma yana iya juriya ga ƙwayoyin halitta. Ganin cewa babu wani nau'ikan rayuwa da aka buga don maye gurbin *E. coli* ta amfani da Hasken ultraviolet (UV), Witkin da farko ya zaɓi allurai waɗanda suka zama masu girma. Yawancin mazaunanta sun mutu, amma hudu sun tsira a farantin daya. Idan aka kwatanta da nau'in iyaye, waɗancan ƙwayoyin cuta sun nuna haƙuri mafi girma ga radiation na UV. Ta kuma lura cewa akwai bambance-bambance a cikin halayyar kwayar cutar idan aka kwatanta da nau'ikan daji: nau'ikan masu tsayayya ba su nuna jinkiri ba kafin rarraba tantanin halitta da ci gaban tsaunuka masu tsawo da filamentous, dukansu an gani a cikin nau'ikan UV-sensitive. Witkin shine mai bincike na farko da ya ware maye gurbin da ke ba da juriya ga radiation na UV.