Endemic species are defined as taxa that naturally inhabit and grow within a specific area. Because they easily face regional extinction, continuous management is required. In this study, stable isotope analysis, length-weight relationships (LWRs), and condition factor (K) estimation were applied to oily bitterling Acheilognathus koreensis inhabiting three representative rivers including the Geum River basin, Seomjin River basin, and Tamjin River basin to compare ecological property and related biological conditions. Based on the corrected isotope value to account for difference in carbon isotope ratio (δ13C) of POM, Δδ13CA.koreensis-POM, estimated isotope niche areas of A. koreensis between Geum and Tamjin River populations were highly overlapped while those of the Seomjin River population were discriminated from other habitats, indicating differences in major diet sources among habitats. In addition, LWRs for the Seomjin River population showed a good growth with a b value of 3.155 compared to Geum and Tamjin River populations which showed relatively low growth rates of 2.888 and 2.968, respectively. Fluctuation of the K value of the A. koreensis tended to decrease with growth in the Geum River while that of the Seomjin River population exhibited the highest increasing trend. This study confirmed differences in diet resources among habitats for A. koreensis, which resulted growth and fatness variations for each population. Our results can be used as basic information for effective conservation and management strategies of A. koreensis populations.
Cloned calves derived from somatic cell nuclear transfer (SCNT) have been frequently lost by sudden death at 1 to 3 month following healthy birth. To address whether placental anomalies are responsible for the sudden death of cloned calves, we compared protein patterns of 2 placentae derived from SCNT of Korean Native calves died suddenly at two months after birth and those of 2 normal placentae obtained from AI fetuses. Placental proteins were separated using 2-Dimensional gel electrophoresis. Approximately 800 spots were detected in placental 2-D gel stained with coomassie-blue. Then, image analysis of Malanie III (Swiss Institute for Bioinformatics) was performed to detect variations in protein spots between normal and SCNT placentae. In the comparison of normal and SCNT samples, 8 spots were identified to be up-regulated proteins and 24 spots to be down-regulated proteins in SCNT placentae, among which proteins were high mobility group protein HMG1, apolipoprotein A-1 precursor, bactenecin 1, tropomyosin beta chain, H+-transporting ATPase, carbonic anhydrase II, peroxiredoxin 2, tyrosine-rich acidic matrix protein, serum albumin precursor and cathepsin D. These results suggested that the sudden death of cloned calves might be related to abnormal protein expression in placenta.
The gonadosomatic index (GSI), gonadal development and changes in hormones in plasma level of the indoor cultured grunt (Hapalogenys nitens) were investigated by histological study from August 2011 to October 2012. The GSI showed similar trends with gonad developmental stages during the culture periods. Changes in plasma level of estradiol-17β of female H. nitens reached the highest value before the spawning period, and seasonal changes in plasma level of estradiol-17β were similar in trends of oocyte developments and GSI changes. Testosterone levels of male H. nitens reached the highest value before and after the spent stage. Ovarian developmental stages of H. nitens could be classified into early growing stage, late growing stage, mature stage, ripe and spawning stage, recovery and resting stage. The testicular developmental stages could be divided into growing stage, mature stage, ripe and spent stage, and recovery and resting stage.