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1.
Summary Five species ofChiroptera were studied and the following numbers were found:Rhinolophus hipposideros Bechst.N=27;Barbastella barbastellus Schr.N=16;Plecotus auritus L.N=16;Myotis myotis Bork.N=21;Miniopterus schreibersii Kuhl,N=23. Centric fusions occur in the chromosomal evolution ofChiroptera. Sex-chromosomes ofX-Y type. 相似文献
2.
R. Matthey 《Cellular and molecular life sciences : CMLS》1958,14(7):240-241
Summary (1)Ellobius lutescens andMicrotus oregoni show the same type of sex-chromosomes. The diploid number is odd in both sexes, seventeen.(2) The odd element ofEllobius is morphologically alike in the male and in the female. InM. oregoni, the odd element of the male is acrocentric, that of the female metacentric.(3) Following a hypothesis ofWhite, it seems very probable that the heterochromosome of the male is built of the primitiveY (short arm) and the primitiveX (long arm) linked together. In the female of the same species (M. oregoni), the sex-chromosome represents both theX fused together.(4) Only the half of the Zygotes may develope, the other half being lethal.(5) The close kinship betweenEllobius andM. oregoni is certain, a parallel evolution appearing as highly improbable. 相似文献
3.
R. Matthey 《Cellular and molecular life sciences : CMLS》1968,24(11):1160-1161
Summary As contribution to the problem of the Australian endemic Muridae, the chromosome complement ofLeggadina h. hermannsburgensis is described: 2N=48 –N.F.=56 –X-chromosome big and metacentric. 相似文献
4.
R. Matthey 《Cellular and molecular life sciences : CMLS》1967,23(2):133-134
Summary The author treats 2 topics connected with his studies on the cytogenetics of the African pigmy-mice. (1)Mus (Leggada) bufo Th. shows the primitive complement already detected in other species or subspecies (minutoides ssp
1,indutus, tenellus, setulosus): 2N=36,N.F.=36, sex chromosomesPR. (2) The deletion of the short arm of oneX-chromosome (X
dc
) was previously observed as heterozygous mutation by 4 in a sample of 7 and 5 . A more important sample (18 , 21 ) gives the following results: 11 X-X, 10 X-X
dc
, 18 X-Y. The occurrence of X
dc
-X
dc
and of X
dc
-Y is also very improbable. It is not easy to understand how the chromosomeX
dc
may persist in the population if the complementsX
dc
-X
dc
andX
dc
-Y are lethal, which seems to result from these observations. 相似文献
5.
Summary The author shows that the conception of an incomplete sex-linkage in mammals must be discarded on cytological grounds. There is either (general case) pre-reduction of theX andY chromosomes at the first metaphase, or post-reduction (Apodemus) but never facultative post-or pre-reduction.During the growth period, from the Zygoteny to the Diacinesis, the occurrence ofc -o is made highly improbable, owing to the heteropycnotic state of the sexchromosomes, and has never been observed with accuracy. The revision of the literature shows that such an hypothesis is not tenable.The obligatory post-reduction byApodemus can be interpreted in the concept of anticipation centromérique.In a very few cases, formations like chiasmas occur as linking theX andY chromosomes at the first metaphase. It is possible that these exceptional configurations might be explained by a translocation of the sex-chromosomes on a pair of autosomes.From a more general standpoint, it would be desirable that geneticians should have more confidence in the results of pure cytologists rather than in the work of cytogeneticians who wish to find an explanation for every genetical hypothesis.
Institut de Zoologie et d'Anatomie comparée. 相似文献
Institut de Zoologie et d'Anatomie comparée. 相似文献
6.
R. Matthey 《Cellular and molecular life sciences : CMLS》1946,2(12):497-498
Summary The chromosomal sets of five species ofPerlodidæ (Plecoptera) are given in the present paper. The sexual chromosomes belong to three distinct types:X-O,X
1-X
2,X
1-X
2-X
3. The author shows that these three types are likely derived from the most primitive patternX-Y, by translocation and inversion. 相似文献
7.
R. Matthey 《Cellular and molecular life sciences : CMLS》1958,14(7):256-256
8.
9.
R. Matthey 《Cellular and molecular life sciences : CMLS》1945,1(2):50-56
Sans résumé 相似文献
10.
R. Matthey 《Cellular and molecular life sciences : CMLS》1946,2(7):260-261
Summary The males of two species of Palestine,Saga ephippigera
Fisch. andS. gracilipes
Uvar have respectively 33 and 31 chromosomes in the diploid state.S. pedo
Pallas, a parthenogenetic thelytoc species largely distributed in Europe, has 68 chromosomes and probably represents a tetraploid. The cells of the three species have identical dimensions and the polyploidS. pedo is even the smallest in size. 相似文献