C-banding karyotypes and location of NOR's in the toad species Bufo bufo and Bufo viridis from Yugoslavia

The karyotypes, C-banding patterns and positions of nucleolus organizer regions (NORs) of two European species of toads, Bufo bufo and Bufo viridis from seven localities in Yugoslavia were investigated. These karyotypes and chromosomal markers were compared with those in other species and subspecies of the Bufo bufo complex. The results suggest that C-banded patterns are characters specific for those species. A marker band on chromosome 5 in the karyotype of B. bufo bufo is shown.Ispitivani su kariotipovi, C-trake i položaj nukleolusnih organizatora (NOR) dve evropske vrste žaba, Bufo bufo i Bufo viridis, sa 7 jugoslovenskih lokaliteta. Kariotipski i hromozomalni markeri ovih vrsta poređeni su sa podacima koji se odnose na druge vrste i podvrste. Rezultati ukazuju da je raspored C-traka specifične za ispitivane vrste. Kod vrste B. bufo bufo nađena je marker traka na petom hromozomu.Projekat ministarstva br. 03E0

B Chromosomes in Populations of Mammals Revisited

The study of B chromosomes (Bs) started more than a century ago, while their presence in mammals dates since 1965. As the past two decades have seen huge progress in application of molecular techniques, we decided to throw a glance on new data on Bs in mammals and to review them. We listed 85 mammals with Bs that make 1.94% of karyotypically studied species. Contrary to general view, a typical B chromosome in mammals appears both as sub- or metacentric that is the same size as small chromosomes of standard complement. Both karyotypically stable and unstable species possess Bs. The presence of Bs in certain species influences the cell division, the degree of recombination, the development, a number of quantitative characteristics, the host-parasite interactions and their behaviour. There is at least some data on molecular structure of Bs recorded in nearly a quarter of species. Nevertheless, a more detailed molecular composition of Bs presently known for six mammalian species, confirms the presence of protein coding genes, and the transcriptional activity for some of them. Therefore, the idea that Bs are inert is outdated, but the role of Bs is yet to be determined. The maintenance of Bs is obviously not the same for all species, so the current models must be adapted while bearing in mind that Bs are not inactive as it was once thought

Chromosome status of marsh marigold, Caltha palustris L. (Ranunculaceae) from Serbia

Marsh marigold, Caltha palustris is distributed in the moist, temperate and cold regions of the Northern Hemisphere. This species exhibits considerable amount of intraspecific chromosomal diversity involving hybridization, polyploidy, aneuploidy and B chromosomes. Karyotype analyses of three mountain populations from Serbia were done for the first time. All samples were tetraploid (based number x=8) with 2n=32. In population from mountain Tara presence of one B chromosomes was detected. Tetraploid karyotype consists of 17 median-centromeric (m), 8 submedian-centromeric (sm), 7 subterminal-centromeric (st) chromosomes and one terminal-centromeric (t) B chromosome (2n= 17m+8sm+7st+1B). Studied populations in Serbia belong to the most common cytotype for this species in Europe.Kaljužnica, Caltha palustris, naseljava vlažne, umerene i hladne predele severne hemisfere. Ovu vrstu karakteriše znatna količina intraspecijske hromozomske varijabilnosti uključujući hibridizaciju, poliploidiju, aneuploidiju i B hromozome. Po prvi put je urađena kariotipska analiza tri planinske populacije iz Srbije. Svi analizirani uzorci su bili tetraploidi (osnovni broj n=8) sa 2n=32. U populaciji sa planine Tare detektovano je prisustvo jednog B hromozoma. Tetraploidni kariotip se sastojao od 17 metacentričnih (m), 8 submetacentričnih (sm), 7 subtelocentričnih (st) i jednog telocentričnog (t) B hromozoma (2n=17m+8sm+7st+1B). Analizirane populacije iz Srbije pripadaju citotipu koji je najčešći za ovu vrstu u Evropi.Projekat ministarstva br. 17300

Ponašanje atipičnih klijanaca kukuruza u poljskoj proizvodnji

The aim of this study was to investigate field emergence parameters, number of plants that reached reproductive stage and yield of seed lots with different count of abnormal seedlings. In standard germination test these seedlings are discarded from the count of germinated seed, presuming that they will not develop into normal plants. Five lots of hybrid NS 640 with different percentage of abnormal seedlings were tested. Results showed that in favourable environment conditions, large number of abnormal seedlings emerged, reached reproductive stage and participated in yield formation. However, emergence of seed lots with high percentage of abnormal seedlings was longer than for lots with small number of abnormal seedlings. Laboratory germination and germination energy were more correlated with indicators of field emergence rate, while total percentage of germinated seedlings (normal and abnormal) was more correlated with grain yield. However, it can be expected that in adverse environment conditions, abnormal seedlings are less likely to develop into normal plants.Cilj ovog ispitivanja bio je da se kod partija semena sa različitim udelom atipičnih ponika ispitaju parametri brzine klijanja u polju, broj biljaka u reproduktivnoj fazi i prinos. Ovakvi ponici se u standardnom testu klijavosti ne ubrajaju u klijava zrna, jer se pretpostavlja da neće dati normalnu biljku. Testirano je pet partija hibrida NS 640 sa različitim udelom atipičnih ponika. Rezultati su pokazali da je u povoljnim uslovima veliki broj atipičnih klijanaca nikao, dostigao reproduktivnu fazu i učestvovao u formiranju prinosa. Sa druge strane, nicanje partija sa velikim brojem atipičnih klijanaca je bilo usporeno. Laboratorijska klijavost i energija klijanja su bile u većoj korelaciji sa parametrima brzine nicanja, dok je ukupna klijavost (normalni i atipični klijanci) bila u većoj korelaciji sa prinosom. Ipak, u nepovoljnim uslovima spoljašnje sredine, atipični klijanci imaju manje šanse da se razviju u normalnu biljku

C-banding karyotypes and location of NOR's in the toad species Bufo bufo and Bufo viridis from Yugoslavia

The karyotypes, C-banding patterns and positions of nucleolus organizer regions (NORs) of two European species of toads, Bufo bufo and Bufo viridis from seven localities in Yugoslavia were investigated. These karyotypes and chromosomal markers were compared with those in other species and subspecies of the Bufo bufo complex. The results suggest that C-banded patterns are characters specific for those species. A marker band on chromosome 5 in the karyotype of B. bufo bufo is shown.Ispitivani su kariotipovi, C-trake i položaj nukleolusnih organizatora (NOR) dve evropske vrste žaba, Bufo bufo i Bufo viridis, sa 7 jugoslovenskih lokaliteta. Kariotipski i hromozomalni markeri ovih vrsta poređeni su sa podacima koji se odnose na druge vrste i podvrste. Rezultati ukazuju da je raspored C-traka specifične za ispitivane vrste. Kod vrste B. bufo bufo nađena je marker traka na petom hromozomu.Projekat ministarstva br. 03E0

Chromosome status of marsh marigold, Caltha palustris L. (Ranunculaceae) from Serbia

Marsh marigold, Caltha palustris is distributed in the moist, temperate and cold regions of the Northern Hemisphere. This species exhibits considerable amount of intraspecific chromosomal diversity involving hybridization, polyploidy, aneuploidy and B chromosomes. Karyotype analyses of three mountain populations from Serbia were done for the first time. All samples were tetraploid (based number x=8) with 2n=32. In population from mountain Tara presence of one B chromosomes was detected. Tetraploid karyotype consists of 17 median-centromeric (m), 8 submedian-centromeric (sm), 7 subterminal-centromeric (st) chromosomes and one terminal-centromeric (t) B chromosome (2n= 17m+8sm+7st+1B). Studied populations in Serbia belong to the most common cytotype for this species in Europe.Kaljužnica, Caltha palustris, naseljava vlažne, umerene i hladne predele severne hemisfere. Ovu vrstu karakteriše znatna količina intraspecijske hromozomske varijabilnosti uključujući hibridizaciju, poliploidiju, aneuploidiju i B hromozome. Po prvi put je urađena kariotipska analiza tri planinske populacije iz Srbije. Svi analizirani uzorci su bili tetraploidi (osnovni broj n=8) sa 2n=32. U populaciji sa planine Tare detektovano je prisustvo jednog B hromozoma. Tetraploidni kariotip se sastojao od 17 metacentričnih (m), 8 submetacentričnih (sm), 7 subtelocentričnih (st) i jednog telocentričnog (t) B hromozoma (2n=17m+8sm+7st+1B). Analizirane populacije iz Srbije pripadaju citotipu koji je najčešći za ovu vrstu u Evropi.Projekat ministarstva br. 17300

Is there a host sex bias in intestinal nematode parasitism of the yellow-necked mouse (Apodemus flavicollis) at Obedska bara pond, Serbia?

Fifty-one yellow-necked mice from the Obedska bara locality were analysed for the presence of intestinal nematode parasites in order to assert whether there was a host sex bias in infection. Previous research indicated that males would be the more infected sex, either due to the immunosuppressive effect of testosterone or their different allocation of resources towards immune defence. Quantitative infection parameters were compared between host sexes for all nematode species and nematodes in general. In addition, the influence of host sex, age, total body length, body mass and presence of other nematode species on parasite abundance was analysed. No statistically significant differences between males and females were noted for any of the studied quantitative parameters, leading to an absence of sex-biased parasitism in this study

One more Microtus species with asynaptic sex chromosomes

Arvicoline voles are known as a karyotypically extremely polymorphic group in which the genus Microtus leads with the highest rate of karyotype change. A member of this genus, the European pine vole Microtus subterraneus (de Selys-Longchamps, 1836), is widely distributed in Europe and parts of Asia. There are two cytotypes differing in diploid chromosome number, 2n=54 and 52, each showing different chromosomal polymorphisms. At two localities in southeastern Serbia, Mt. Jastrebac and Vlasina, we found the 2n=52 cytotype. Meiotic preparations from males revealed the presence of asynaptic sex chromosomes. Although asynaptic sex chromosomes are frequent in Microtus, this is the first finding for M. subterraneus. From summarized data it appears that two-thirds of the studied species, mainly from Microtus and Terricola subgenera, possess asynaptic sex chromosomes

Population genetic structure of the Mediterranean horseshoe bat Rhinolophus euryale in the central Balkans.

Migratory behaviour, sociality and roost selection have a great impact on the population structure of one species. Many bat species live in groups, and movements between summer and hibernation sites are common in temperate bats. The Mediterranean horseshoe bat Rhinolophus euryale is a cave-dwelling species that exhibits roost philopatry and undertakes seasonal movements which are usually shorter than 50 km. Its distribution in Serbia is restricted to karstic areas in western and eastern parts of the country, with a lack of known roosts between them. In this study, microsatellite markers were used to evaluate genetic variation in this species in the Central Balkans. Specifically, spatial genetic structuring between geographic regions and relatedness within different colony types were assessed. All analysed loci were polymorphic, and there was no significant inbreeding coefficient recorded. A moderate degree of genetic differentiation among the sampled colonies was found, and significant isolation by distance was recorded. Our results revealed that populations show a tendency to segregate into three clusters. Unexpectedly, populations from Montenegro and Eastern Serbia tended to group into one cluster, while populations from Western Serbia and Slovenia represented second and third cluster, respectively. The majority of variance was partitioned within colonies, and only a small but significant portion among clusters. Average relatedness within colony members was close to zero, did not differ significantly between the different colony types, and kinship is unlikely to be a major grouping mechanism in this species