OBJECTIVE: To evaluate the incidence of chromosomal abnormalities in ectopic pregnancy chorionic villi. METHODS: A prospective study of patients with the diagnosis of ectopic pregnancy was conducted, with chorionic villi obtained at the time of surgical therapy cultured and analyzed for karyotype. Review of the patient's medical record and ultrasound evaluation was then completed and findings correlated with karyotype results. RESULTS: Twenty- two patients undergoing surgery for the diagnosis of ectopic pregnancy yielded chorionic villi for culture. Successful culture was performed in 21 patients, with 3 (14%) revealing abnormal karyotypes. Review of the medical record showed ultrasound results consistent with fetal development or a gestational sac in 15 of 18 patients with normal chromosomal analysis. Three of 6 patients without fetal development yielded abnormal chromosomal findings. CONCLUSION: Our results confirm that a high degree of success can be achieved in the karyotype analysis of ectopic pregnancy chorionic villi and that these conceptuses have a rate of abnormality similar to that reported for intrauterine gestations. Our data further suggest that when a gestational sac or fetal pole is identified by ultrasound, there is usually a normal karyotype.

No description available.

Oxymonads are a group of flagellate protists living in low oxygen environments - mainly the guts of insects and vertebrates. In this study, we focus on the analysis of ploidy and karyotype of various species of oxymonads using Fluorescence In Situ Hybridization (FISH) with probes against single copy genes and telomeric repeats as well as estimating the DNA content in the nuclei of these oxymonads using flow cytometry. Using specific FISH probes against SufDSU gene, which is present in a single copy in the haploid genome, we showed that all studied strains are probably haploid. From the genome of Monocercomonoides exilis strain PA203 we know that oxymonads have the ancestral type of telomeric repeat (TTAGGG). Using a probe against these repeats we tried to label chromosome ends and estimate the number of chromosomes for seven strains (five species) of Monocercomonoides. With a single exception, the average number of signals per nucleus was below 20 indicating number of chromosomes below 10. In the strains of M. mercovicensis, we observed much higher number of signals suggesting that the cells have much higher number of chromosomes. Finally, we established the DNA content for several strains using flow cytometry. We used as a standard M. exilis strain PA203 knowing that the haploid genome size is...

There is a vast diversity of karyotypes in nature, yet mechanisms that have facilitated such diversity are unclear. Alterations to an organism’s karyotype can have major negative fitness consequences in meiosis through non-disjunction and aneuploidy. Here, I investigated the role of biased segregation in female meiosis, i.e., meiotic drive, as a force that contributes to the evolution of karyotype form. The closely related species pair, Drosophila americana and Drosophila novamexicana, is an exemplar for understanding mechanisms of karyotype evolution. Since their recent divergence nearly half a million years ago, D. americana has evolved two different centromeric fusions: one fusion between the 2nd and 3rd chromosomes (Muller elements C and D), and the other fusion between the X and 4th chromosomes (Muller elements A and B). The 2-3 fusion is fixed in D. americana. However, the X-4 centromeric fusion remains polymorphic within the species. I uncovered biased transmissions for both fused chromosomes in D. americana such that the X-4 fused chromosome was inherited by 57% of the offspring from heterozygous females and the 2-3 chromosome was inherited by 62% of the offspring. Introgression experiments shoed the fused X-4 and the unfused X and 4th chromosomes are segregating at a 50/50 ratio in D. novamexicana. I have isolated the fused X-4 centromeric region as a possible player in the observed meiotic drive. However, the centromere is not sufficient to cause meiotic drive without a secondary factor. I also measured heterochromatin content between the fused and unfused X and 4th homologs. No obvious size differences were uncovered, but possible compositional differences were revealed. This suggests that if the centromere itself is involved in meiotic drive, either differences in the number of centromeres or compositional differences between the centromeres are influencing meiotic drive. Overall, I have identified and characterized meiotic drive as a force driving karyotype evolution in D. americana but appears to be absent in D. novamexicana, and I have begun to dissect the mechanisms of meiotic drive.

No description available.

Abstract Most male individuals of all species of the genus Scarus which were reversed from females, are called ¡§secondary males¡¨. However, a few individuals of ¡§primary males¡¨ would have male¡¦s reproductive ability, but never process sex reversal in their lifespan, and keeping female¡¦s outlook (initial phase). Because parrotfishes have these two kinds of males existing in the same species, they belong to ¡§diandry¡¨ protogynous hermaphroditisms. Previous studies suggested that the mechanisms that cause primary male might be due to social effect or genetic control. In our experiments, Blue barred parrotfish (Scarus ghobban) and rivulated parrotfish (Scarus rivulatus) were used to study the sex reversal model of parrotfish and the possible reasons that cause the juveniles develop to be primary males. This study including three major parts: (1) the relationship between body size and sexual types of two species. (2) the comparison of the tissue structures of the testes in both male types by histological observation. (3) the possible karyotypes difference, i.e. the genetic differences between primary and secondary male. This study shown that the body size of blue barred parrotfish (initial phase: 100-475 mm; terminal phase: 275-525 mm) were larger than rivulated parrotfish (initial phase: 126-270 mm; terminal phase: 246-350 mm), and there was a wider overlap zone between both color phases in Blue Barred parrotfish (S. ghobban: 47.2%, then S. rivulatus: 10.7%). Histological results showed that no matter primary or secondary males, they all had classical lobular testes. But, by contrast of the pure testis tissue of primary male, there were many mature or atric oocytes that remained in the testis of secondary male. Additionally, a few secondary males of the blue barred parrotfish were discovered whose process of sex reversal occurred earlier or faster than that for normal secondary males. Histological evidence further suggested that these individuals had never had a female reproductive function. Furthermore, these males which had no difference with other secondary males was found on the chromosome level. In our study, a heteromorphic chromosome was observed between primary males and secondary males of the rivulated parrotfish (Scarus rivulatus), which could prove that being a primary male is predetermined by a genetic factor. Based on the ecological interactive diversity of the two species, a preliminary hypothesis was put forth to explain those phenomena. Due to the spawning tactics used, the proportion of primary males in rivulated parrotfish populations is much higher than that in blue-barred parrotfish populations. On the other hand, the appearance of premature males was suggested to be a way of supplying sperm which was lacking in the population of the blue-barred parrotfish.

A case is presented in which flow cytometric and cytogenetic analysis was done on a biopsy from a highly anaplastic metastatic adenocarcinoma. Flow cytometric analysis of DNA content failed to show a significant population of aneuploid cells. However, histologic examination revealed a substantial number of tumor cells, and cytogenetic analysis produced chromosome counts ranging from 20 to 144.

The aim of presented work is to provide characteristics of the karyotypes of scorpions of the genus Euscorpius. Genus Euscorpius is a typical representative of scorpions in Europe. Its occurrence is wide throughout Europe. Until now, 18 species of this genus have been described. In this work six species were karyologically analyzed and one species was shown to possess only basic diploid number of chromosomes: E. carpathicus - 2n=90, E. concinnus - 2n=88, E. hadzii - 2n=68, E. sicanus - 2n=66, E. tergestinus - 2n=60, E. naupliensis - 2n=60, E. italicus - 2n=36. Description of the karyotypes revealed that all species studied exhibit achiasmatic meiosis; no presence of sex chromosomes was detected. The basic hypothesis of phylogenetic relationships and karyotype evolution of the genus Euscorpius was outlined. High interspecies variability in chromosome total count was found and by analysis of the 16S rRNA gene the taxonomic status of the species was confirmed. Hence, it seems that cytogenetic methods can contribute to the understanding of species diversity and differentiation of possible cryptic species within the genus Euscorpius.

Giardia intestinalis is a parasitic protist that causes one of the most common diarrheal disease of parasite origin. The cell of Giardia contains two nuclei with unknown number of chromosomes until recently. Karyotype was determined five years ago using conventional cytogenetic method by Tůmová and collaborators. In my work, I assessed karyotype of four isolates, six lines and three clonal lines by the same method. It was confirmed, that two nuclei within one cell could differ in chromosome number, the differences found were 1, 2 or 6 chromosomes. Aneuploid number of chromosomes was found too. In case that both nuclei within single cell contained the same number of chromosomes, there were 10 chromosomes indentified in each nucleus. It was also revealed, that karyotype is not specific feature for different genetic groups (in this work assemblages A and E). Karyotype can be different even among lines and clonal populations derived from the same isolate. Changes in karyotype in the course of in vitro cultivation were detected within three populations. Results are discussed in relation to known facts.

This master's thesis is focused on cytogenetic analysis and karyotype variability of the Nemastomatidae family. This family comprises morphologically uniform harvestmen of small sizes, with low mobility, and with center of distribution in Europe. Karyotype differences could play an important role for detection of cryptic diversity in this family. The karyotype analysis is focused mainly on Alpine and Pyrenean endemic species but also on other taxons located in Central Europe. The goal was not only to identify the differences which occur between the specific genera and species, but also eventually between populations. For detection of the specific chromosomal alterations in evolution of the karyotype in Nemastomatidae the fluorescent in situ hybridization (FISH) was used, localizing the positions and amounts of gene clusters for 18S rRNA. From the results we can assume that the number of chromosomes in the family Nemastomatidae can range between 2n = 12- 30. Further it was found out that in Nemastomatidae the biarmed chromosomes are more prevalent, and that the species which have lower amounts of chromosomes contain chromosomes that noticeably differ in size (probably because of chromosomal fusions). These results indicate that with some morphologically uniform species, the knowledge of specific...