Landscape pattern and genetic structure of a yellow-necked mouse <Emphasis Type="Italic">Apodemus flavicollis</Emphasis> population in north-eastern Poland

Reduced connectivity among local populations inhabiting a spatially heterogeneous landscape may restrict gene flow and thus contribute to diminished genetic variation within a population. The aim of this study was to determine the role of geographic distance and habitat barriers in developing genetic structure of a yellow-necked mouse Apodemus flavicollis (Melchior, 1834) population, taking into consideration the spatial organization of the landscape. A field study was carried out in two plots located in NE Poland that differed considerably in terms of the scale of habitat fragmentation: (1) a continuous forest complex, and (2) a mosaic of smaller forest habitats. The plots were separated by a water barrier comprised of a chain of lakes. DNA samples from a total of 654 individuals were examined by microsatellite analysis (5 loci). The results showed that the yellow-necked mouse population was characterized by a poorly pronounced genetic structure throughout the study area, although the statistical significance of F _ST for most location pairs indicated that gene flow in the area was not free. The division of the mouse population into three genetically distinct groups clearly demonstrated the significant role of water bodies as a natural barrier effectively hindering free movement of animals and thus gene flow. Analysis of the genetic structure of the mouse population throughout the study area and also within the distinguished groups indicated that the entire study population may be considered as a single metapopulation. Our results suggest that geographic distance alone is not the predominant factor affecting the genetic structure of population, but in the mosaic landscape the relative isolation of individual forest fragments, and barriers hindering movements of individuals and limiting gene flow among local populations played a much more important role.     

Effect of addition of buserelin acetate to the extender on motility and viability of bovine spermatozoa

The present study was aimed to determine the effect of GnRH analog (buserelin acetate) on the quality of bovine spermatozoa stored at 16°?C for 24?h. Semen collected in the summer season from June to September from healthy Polish Holstein–Friesian bulls. Ejaculates were centrifuged, divided and diluted to the final concentration of 240?×?10⁶ spermatozoa/mL using animal protein–free commercial BIOXcell^® extender (IMV Technologies, L’aigle, France) (Control) or with BIOXcell^® extender supplemented with buserelin acetate and stored 0, 8 and 24?h. Sperm motility parameters analysis was performed using a computer-assisted sperm analysis (CASA) system. The viability of spermatozoa was performed using flow cytometer. The addition of buserelin acetate to BIOXcell^® extender did positively affect the total motility (was higher in the observed samples with the addition of 2?µg/mL and 4?µg/mL than in the control group), progressive motile (forward progressing sperm was significantly increased (p?<?0.05) over the control group at the 0?h and 8?h of incubation following the supplementation of 2, 4 and 8?μg/mL buserelin acetate) and viability of spermatozoa (the number of live spermatozoa was significantly higher (p?<?0.05) in 2?µg/mL and 4?µg/mL samples with buserelin acetate at 8th hour of incubation and in sample with 4?µg/mL at 24th hour of incubation compared to the control group). We recommend adding 4?µg/mL to the extender to improve the quality of bovine semen.     

High incidence of mental retardation in Turner syndrome patients with ring chromosome X formation

In this report we describe and comment the high incidence of mental subnormality in a series of 21 Turner syndrome patients with ring chromosome X, diagnosed in Leuven in the period 1965-1989. In 7 of the 21 (one third) a varying degree of mental retardation, from borderline intelligence to severe mental retardation was found. In 4 of them (18.5%) mental retardation was moderate to severe.     

The fetal phenotype in 15q2 duplication

In this report we summarize the findings in a prenatally diagnosed male fetus with 15q2 trisomy. The craniofacial findings were identical to those in liveborn patients with this type of partial autosomal trisomy. A short review of the 15q2 trisomy syndrome is presented.     

47,XXY karyotype in a patient with Beckwith-Wiedemann syndrome

The present report summarizes the follow-up data from birth up to the age of 14 years in a male patient with Beckwith-Wiedemann syndrome and 47,XXY karyotype.     

Reciprocal translocations and full trisomy (trisomy 18 and trisomy 21) in the offspring

In this report, we present examples of trisomy 18 and trisomy 21, both resulting from maternal reciprocal translocations: 46, XX, t(5;18) (q21;q11) and 46, XX, t(5;21) (p11.2;p11), respectively.