Detection of Mouse Tyrosinase With a Monoclonal Antibody MAT-1 Against Human Tyrosinase

In this study we explored the possible application of MAT-1, which has been established as a monoclonal antibody against human tyrosinase, for detection of mouse tyrosinase. The MAT-1 reacted with B16 mouse melanoma cells, but not with tyrosinase-negative NIH-3T3 mouse fibroblasts. In western blot analysis of the large granule fraction (LGF) of B16 cells, MAT-1 detected a single protein of 80 kDa, whose size was close to that of human tyrosinase detected with MAT-1 in extracts of human melanocytes. Furthermore, the 80 kDa band that was detected with MAT-1 in the LGF of B16 cells was also detected by DOPA reaction. In order to confirm that the protein detected with MAT-1 is tyrosinase, a transient expression assay was carried out. When mouse tyrosinase or mouse tyrosinase-related protein 1, which shares high homology with human tyrosinase, was transiently expressed in tyrosinase-negative K1735 mouse melanoma cells by cDNA transfection, MAT-1 reacted only with the cells expressing mouse tyrosinase. These results indicate that MAT-1 specifically reacts with mouse tyrosinase.     

Cell Fusion and Its Application to Genetic Analysis of Development in Dictyostelium discoideum

Dictyostelium cells were fused by a modification of the polyethylene glycol method of Kuhn and Parish. In the modified method Tricine buffer and Concanavalin A were used in place of Ca⁺⁺. The efficiency of genetic complementation through cell fusion was about 10 times higer by the modified method than by the original method with glycine buffer and Ca⁺⁺. Complementation between developmental mutants without any selectable growth character was clearly detected by the modified system, at efficiencies of about 1 in 10–20 surviving cells.     

Molecular phylogeny of wood mice (Apodemus, Muridae) in East Asia

Sequences of the mitochondrial cytochrome b (1140 bp) and nuclear IRBP (1152 bp) genes were used to assess the evolutionary history of Apodemus , using the complete set of Asian species. Our results indicate that speciation in Asia involved three radiations, which supports an earlier study. The initial radiation yielded A. argenteus (Japanese endemic), A. gurkha (Nepalese endemic), and the ancestral lineage of the remaining Asian species. This lineage subsequently diverged into four groups: agrarius-chevrieri ( agrarius group), draco-latronum-semotus ( draco group), A. peninsulae , and A. speciosus (Japanese endemic). The final step consisted of divergence within two species groups as a consequence of the geography of the Yunnan-Guizhou plateau and Taiwan. The ecological ability of two Apodemus species to inhabit one locality via niche partitioning likely drove the second radiation and shaped the basic geographical pattern seen today: A. argenteus and A. speciosus in Japan, A. agrarius and A. peninsulae in northern China, and the A. agrarius and A. draco groups in southern China. The three radiations are estimated to have occurred 7.5, 6.6, and 1.8–0.8 Mya respectively, using the IRBP clock, based on rat–mouse divergence 12 Mya.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 469–481.     

A simple method to score single nucleotide polymorphisms based on allele‐specific PCR and primer‐induced fragment‐length variation

We describe a simple protocol to genotype single nucleotide polymorphisms (SNPs), which combines allele‐specific polymerase chain reaction (PCR) with fragment‐length analysis. Three primers are used in the PCR: two allele‐specific forward primers with a length‐difference and one reverse primer. The forward primers induce a length‐difference between the SNP‐variants, which can be assessed with standard fragment‐length analyses. We designed primers for 21 SNPs, and codominance was achieved for 76% of these SNPs. An inexpensive and flexible laser‐detection scoring protocol can be achieved with multiplex scoring and by incorporating the M13(‐21) genotyping method.     

云南水牛的同期发情、超数排卵和胚胎移植试验

为探讨水牛胚胎移植的效果 ,于 2 0 0 2年对云南水牛进行了胚胎移植试验 :①用国产氯前列烯醇(PG) 0 6mg/头·次处理供、受体水牛的同期发情率和可用率分别为 4 3 33% (13/ 30 )和 16 6 7% (5 / 30 ) ;同期发情率经产水牛高于青年水牛 (P =0 0 86 ) ,杂交水牛高于德宏水牛 (P =0 15 3) ,体重 4 0 1～ 5 30kg水牛显著高于体重 30 0～ 4 0 0kg水牛 (P <0 0 5 ) ;发情明显水牛的可用率极显著高于发情不明显的水牛 (P <0 0 1)。②选用河流型摩拉水牛与沼泽型德宏水牛的杂交一代 5头为供体 ,分进口激素组 (n =2 )和国产激素组 (n =3)进行超数排卵 ,共有 2头获 9枚胚胎 ;进口激素组供体的平均获胚数和可移植胚数分别为 2 0枚和 1 5枚 ,比国产激素组分别多 0 33枚 (P =0 4 5 4 )和 1 17枚 (P =0 2 88)。③所获 4枚可用鲜胚分别移植 3头受体 ,结果 90d的妊娠率为 33 33% ,但最终无一头产犊。试验结果表明使用进口FSH 2 4mg +PG (Lutalyse○R) 35mg和国产FSH 11mg +PG 0 8mg对水牛超数排卵有效 ,同时提示需要足够数量的受体 ,从中选用发情表现明显、黄体发育良好的进行胚胎移植 ,才能取得良好效果。     

Carapace formation of the podocopid ostracode Semicytherura species (Crustacea: Ostracoda)

Details of ostracode carapace structures were examined by SEM and TEM. The podocopine ostracode Semicytherura kazahana has major ridges on the carapace surface and develops its prismatic layer inside the adult carapace. Electron microscopy at the final molt reveals that the major ridges arise from the highly dense formation of pits within the underlying swollen epidermis, and that disappearance of the epidermis in the presumptive area of the prismatic layer occurs after the calcification of the outer lamella cuticle, and just before synthesis of the membranous layer. These facts suggest that the formation of the carapace in Semicytherura takes place via a more complex process than that of the other podocopid ostracodes.