title: [Meiotic chromosomes of green frogs (Rana esculenta complex) of the Ukraine territory].
abstract: In this work meiotic chromosomes of R. ridibunda, R. lessonae and their hybrid form R. esculenta of the Ukraine territory are described for the first time. These chromosomes are connected in diakinesis more often by two chiasma, rarely by one or three chiasma in 13 bivalents. Bivalents with one chiasma in R. ridibunda are typical only for large bivalents, in R. lessonae only for small ones. Three chiasma in parental species are typical only for small bivalents. In the hybrid form R. esculenta chromosomes with two, one and three chiasma are typical both for large bivalents, and for small ones. In the hybrid form (R. esculenta) chiasma frequency noticeably decreases, comparatively with parental species that, possibly, specifies the aberration of normal meiosis realization. The chiasma frequencies of the hybrid form of the eastern and the southern parts of Ukraine are almost the same, but the types of chromosomes are different in such regions. In the eastern region chromosomes of the hybrid form are represented by two or one chiasma, in the southern region by two, one or three chiasma.
authors.forename: N M
authors.initials: NM
authors.lastname: Suriadna
mesh_terms: D000818:Animals; D002875:Chromosomes; D003433:Crosses, Genetic; D008540:Meiosis; D011893:Rana esculenta / Q000235:genetics*; D011895:Rana ridibunda / Q000235:genetics; D011898:Ranidae / Q000235:genetics; D014455:Ukraine