. "GP206/02/P068" . . "Sex ratio in voles - can mothers manipulate sex of their offspring?"@en . . . "Neuvedeno."@en . . . . . . . "1"^^ . . . "Vole population sex ratio has long been known to vary seasonally. However, owing to the long-term research tradition, population proportions were always estimated using naive estimators, which do not allow for biases due to sex differences in capture pro"@en . . "2008-07-23+02:00"^^ . "0"^^ . "2"^^ . "Populace hrabo\u0161\u016F vykazuj\u00ED v\u00FDrazn\u00E9 sez\u00F3nn\u00ED i v\u00EDcelet\u00E9 zm\u011Bny po\u010Detnosti, kter\u00E9 jsou prov\u00E1zeny oscilacemi pom\u011Bru pohlav\u00ED v populaci. Z v\u00FDsledk\u016F p\u0159edchoz\u00EDch studi\u00ED vypl\u00FDv\u00E1, \u017Ee u v\u011Bt\u0161iny druh\u016F hrabo\u0161\u016F p\u0159eva\u017Euj\u00ED v odloviteln\u00E9 \u010D\u00E1sti populace v letn\u00EDm apodzimn\u00EDm obdob\u00ED samice, zat\u00EDmco samci jsou po\u010Detn\u011Bj\u0161\u00ED v zim\u011B a na ja\u0159e. V\u00FDsledn\u00FD pozorovan\u00FD pom\u011Br pohlav\u00ED v populaci je ovlivn\u011Bn p\u011Bti faktory: 1) sekund\u00E1rn\u00EDm pom\u011Brem pohlav\u00ED 2) sexu\u00E1ln\u011B rozd\u00EDln\u00FDm p\u0159e\u017E\u00EDv\u00E1n\u00EDm 3) rozd\u00EDly v prostorov\u00E9 aktivit\u011B samc\u016F a samic4) odli\u0161nou odlovitelnost\u00ED a 5) rozd\u00EDlnou rychlost\u00ED dosp\u00EDv\u00E1n\u00ED jednotliv\u00FDch pohlav\u00ED. V r\u00E1mci navr\u017Een\u00E9ho projektu bude analyzov\u00E1n vliv t\u011Bchto p\u011Bti faktor\u016F na pom\u011Br pohlav\u00ED ve t\u0159ech populac\u00EDch hrabo\u0161e poln\u00EDho (Microtus arvalis). Speci\u00E1ln\u00ED pozornost budev\u011Bnov\u00E1na nitrod\u011Blo\u017En\u00EDmu pom\u011Bru pohlav\u00ED (bude stanoven identifikac\u00ED pohlav\u00ED u embry\u00ED pomoc\u00ED genetick\u00FDch marker\u016F v\u00E1zan\u00FDch na chromoz\u00F3m Y) a p\u0159\u00ED\u010Din\u00E1m a mechanism\u016Fm jeho mo\u017En\u00E9ho vych\u00FDlen\u00ED ve prosp\u011Bch jednoho pohlav\u00ED. Potenci\u00E1ln\u00ED rozd\u00EDly mezi samci a samicemi" . "http://www.isvav.cz/projectDetail.do?rowId=GP206/02/P068"^^ . "2"^^ . . . "0"^^ . . "Pom\u011Br pohlav\u00ED u hrabo\u0161\u016F - mohou matky manipulovat pohlav\u00ED sv\u00FDch potomk\u016F?" . "V minulosti byly v populac\u00EDch hrabo\u0161\u016F zaznamen\u00E1ny v\u00FDrazn\u00E9 sez\u00F3nn\u00ED oscilace pom\u011Bru pohlav\u00ED. Popula\u010Dn\u00ED proporce v\u0161ak byly odhadov\u00E1ny \u010Dasto na z\u00E1klad\u011B odchyt\u016F do sklapovac\u00EDch past\u00ED, p\u0159\u00EDpadn\u011B jin\u00FDch odhad\u016F, kter\u00E9 neumo\u017E\u0148uj\u00ED vyhodnotit vliv odli\u0161n\u00E9 odloviteln"@cs . . . "Vole populations exhibit large seasonal and multi-annual variations in abundance accompanied by changes in population sex ratios. Based on evidence from multiple previous studies, a unique pattern seems to emerge in voles - females predominate in summerand autumn populations, while males are more abundant in winter and spring populations. The sex ratio observed in the population at any instant in time can be affected by five factors: 1) the secondary sex ratio 2) differential survival 3) differentialmovement 4) differential trappability, and 5) differential growth. The proposed project will analyze the effects of these five factors on sex ratio variation in three populations of the common vole (Microtus arvalis). A special attention will be paid onintrauterine sex ratio (by sexing embryos using genetic markers located in chromosome Y) and on causes and mechanisms of possible bias. Potential sexual differences in the next four factors will be assessed by analyzing the data from intensive"@en . . .