A decade of amphibian population genetic studies: synthesis and recommendations

Amphibians are declining globally, and a comprehensive understanding of the spatial distribution of genetic diversity will inform conservation efforts. However, studies that estimate amphibian population genetic structure and gene flow have not yet been synthesized. Our search of literature from 2001 to 2010 yielded 552 amphibian population and landscape genetic studies, of which 139 explicitly estimated gene flow or genetic structure. We examined these works for general trends and conducted a meta-analysis of reported F_ST values. The majority of studies took place in temperate forests in North America and Europe, with no studies of caecilians and few studies of direct-developing species. Among landscape genetic studies, rivers, roads, and mountain ridges were the predominant barriers identified. Conservation status was the only factor that showed a significant relationship with F_ST, with the least concern IUCN status differing significantly from the near threatened (NT) status as well as from any combination of IUCN statuses that included NT. Recent technological advances will help researchers fill taxonomic and geographic research gaps, thereby facilitating management plans that address a greater diversity of amphibian species.     

Comparative analysis of analgesic activities of dermorphin, [DPro<Superscript>6</Superscript>]-dermorphin,and their C-terminal tripeptides

Analgesic activities of dermorphin (DM), [DPro⁶]-DM, and their C-terminal tripeptides were comparatively studied. Analgesic activity was evaluated in tail flick, hot plate, tail pinch, formalin, and acetic acid writhing tests describing different levels of organization of pain sensitivity. Intraperitoneal administration of the peptides decreased the pain threshold in all these tests. The C-terminal tripeptides DM_5–7 and [DPro⁶]-DM_5–7 demonstrated analgesics activity comparable or sometimes higher than that of the full-length molecules. The effect of DM, [DPro⁶]-DM, and C-terminals fragments DM_5–7 and [DPro⁶]-DM_5–7 decreased after co-administration with naloxone, which points to the opioid nature of analgesic activity of the peptides.     

Preliminary study of fish community structure in Amanos Mountain streams (Hatay-Turkey)

Fish diversity and distributions in 33 streams of the Amanos Mountains were investigated between December 2002 and November 2003. Some physical and chemical parameters, such as water temperature, dissolved oxygen, electrical conductivity, pH, and velocity of the streams were measured periodically at each site. The study area was grouped into three regions: AS (Asi Basin), IS (?skenderun Gulf) and CE (Çevlik region). Fish abundance and Shannon Diversity Index were computed for each region. CE region was the poorest compared to the others in terms of fish abundance and diversity. A total of nine species in four families (Cyprinidae, Balitoridae, Anguillidae, Blenniidae) were recorded and all species collected were found to be indigenous. Capoeta barroisi (42.2%) and Garra rufa (33.3%) were the most common and abundant species and Salaria fluviatilis (0.4%), Carasobarbus luteus (0.9%), Anguilla anguilla (1.0%) and Alburnus sellal (1.2%) were the most rarely encountered species in the Amanos Mts. The endangered species Alburnus orontis is also rarely found. Fish diversity was greater in perennial streams (0.62) than in intermittent streams (0.27). There are many adverse human impacts on fish fauna in the Amanos Mountain streams; however, numbers of intermittent streams impose the greatest threat to fish in the Amanos Mts.     

Identification of intestinal M cells in isolated lymphoid follicles and Peyer’s patches of the Angora rabbit

The presence, distribution, and localization of M cells in isolated lymphoid follicles (ILF) and in follicle-associated epithelia (FAE) covering Peyer’s patches (PP) in Angora rabbits were investigated by immunohistochemistry and electron microscopy. Although PP could macroscopically be identified along the length of the mucosal and serosal surfaces of jejunum and ileum, the presence of ILF could only be located microscopically. Typical M cells in FAE were detected within the periphery of the dome regions of the PP, and immature columnar M cells in the FAE resided in the vicinity of the crypts. M cells in the FAE of both ILF and PP showed vimentin-positive reaction. M cells in the FAE of ILF were morphologically similar to the immature M cells found in the FAE of PP. Typical mature M cells were also observed in the FAE of a few ILF. In contrast to FAE of PP, numerous goblet cells were observed in the FAE of many ILF. Moreover, among intestinal villi, we noticed villi-like solitary lymphoid structures that showed abundant lymphocytes in their lamina propria and that were surrounded with vimentin-positive cells and goblet cells. Thus, the occurrence of copious immature M cells and goblet cells, in addition to the detection of villi-like solitary lymphoid structures full of lymphocytes in the FAE of many ILF, indicate that ILF do not complete their immunological maturation in contrast to PP. Various antigenic stimulations conceivably induce the formation and maturation of ILF along the length of the small intestine. The morphological resemblance between ILF M cells and PP M cells suggests that these two types of cells perform similar or the same immunological functions.