Background: Growth-related traits have been mapped on bovine chromosome 6 (BTA 6) in various bovine breed populations. We previously mapped a significant quantitative trait locus (QTL) for carcass and body weight (CW-2) between 38 and 55 cM on BTA 6 using a Japanese Black half-sib family. Additional QTL mapping studies detected four QTL for body or carcass weight that overlapped with CW-2 in Japanese Black and Japanese Brown half-sib families. To map the region in greater detail, we applied cross-breed comparisons of haplotypes that have been shown to be powerful in canine.

Growth hormone secretagogue receptor 1a (GHSR1a) mediates the different actions of its endogenous ligand, ghrelin. Ghrelin-GHSR is involved in many important functions that include growth hormone secretion and food intake. We evaluated the haplotype variety and characterized the microsatellite ((TG)(n) , 5'-UTR) and nucleotide polymorphisms of the bovine GHSR1a gene. The nucleotide sequencing of this gene (∼6 kb) revealed 47 single nucleotide polymorphisms (SNPs), four indels and the microsatellite ((GTTT)(n) , Intron 1). The 19 haplotypes were constructed from all nucleotide viability patterns and were divided into three major groups. Four SNPs (L24V, nt456(G>A), D191N and nt667(C>T)) and DelR242 in Exon 1 and a haplotype block of approximately 2.2 kb (nt667(C>T) ∼ nt2884 (A>G)) were found in Bos taurus breeds. Breed differences in allele frequencies of the two microsatellites, nt-7(C>A), L24V, and DelR242 loci were found (P < 0.005). A DelR242 was found in the Japanese Shorthorn (frequency: ∼ 0.44), Japanese Brown, five European cattle breeds, the Philippine native cattle, but none detected in the Japanese Black or the Mishima island cattle. Additionally, 5'-rapid amplification of cDNA ends and RT-PCR analyses revealed that there were two different kinds of transcripts: spliced, without a microsatellite within 5'-UTR (GHSR1a); and non-spliced, with the microsatellite (GHSR1b).

Our previous study detected a single nucleotide polymorphism (SNP), g.1471620G>T, in the 5' flanking region of the endothelial differentiation sphingolipid G-protein-coupled receptor 1 (EDG1) gene, which has been considered as a positional functional candidate for the gene responsible for marbling, and showed association of the g.1471620G>T SNP with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the g.1471620G>T SNP among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Short Horn, Holstein, and Brown Swiss breeds. The T allele at the g.1471620G>T SNP associated with high marbling was found at high frequency in Japanese Black breed that has been subjected to a strong selection for high marbling, while the allele was absent or at very low frequencies in the other breeds that have not been strongly selected for high marbling. Based on this finding, we hypothesized that the pressure of the strong selection for high marbling in Japanese Black breed has increased the frequency of the T allele at the g.1471620G>T SNP in the EDG1.

Mutations, other than dominant lethals, were accumulated on wild type second chromosomes (+) of Drosophila melanogaster during exposure to 50 Hz sinusoidal alternating magnetic fields of 0.5 or 5 mT (rms) for 40 generations by the Curly/Plum(Cy/Pm) accumulation method. We maintained, for 40 generations under continuous exposure, each (+) chromosome as a heterozygote with (Cy) chromosome. Viability of the (+) chromosome was tested by sib‐mating of (Cy/+) male and (Cy/+) female in a culture every 10th generation to obtain the homozygote. Viability indices, defined as twice the ratio of number of (+/+) flies to that of (Cy/+) flies plus 1 in the progeny of the test mating, also were calculated, which equaled 1.00 at the starting point. For the control and 0.5 and 5 mT exposed groups, percent frequencies of recessive lethal lines, defined as a line with (+/+) flies less than 0.3% in the test mating, were, respectively, 1.9, 0.9, and 2.9% (10th), 9.0, 4.9, and 9.5% (20th), 30.3, 22.9, and 30.4% (30th), and 39.9, 32.4, and 43.3% (40th generation). For the control and 0.5 and 5 mT groups, average viability indices, excluding lethals and markedly deleterious, were, respectively, 0.778, 0.796, and 0.752 (20th), 0.704, 0.698, and 0.694 (30th), and 0.669, 0.678, and 0.595 (40th generation). Their decreasing rates were 0.0054, 0.0059, and 0.0078 per generation. No significant difference was detected among the exposure levels in either the recessive lethal mutation frequency or the viability index. Bioelectromagnetics 19:335–340, 1998. © 1998 Wiley‐Liss, Inc.

Fig. 1. An anteroposterior film of the pelvis obtained one month prior to admission of the patient to the hospital demonstrates extensive permeative destruction of the left innominate bone. A wide zone of transition around the lesion is present. A large extraosseous soft tissue mass is observed HistoryThis 51-year-old m a n was admitted with a six m o n t h history of persistent and worsening pain in the left hip, associated with soft tissue masses in the left groin and right shoulder area, which had been growing over a two m o n t h period. L a b o r a t o r y studies of the b l o o d and urine showed no a b n o r m a l i t y at the time of admission to the hospital. Electrophoretic analysis of the b l o o d serum was within n o r m a l limits. R a d i o l o g i c a l studies (Figs. 1 and 2) showed a rapidly growing destructive lesion of the left innominate bone with a large extraosseous soft tissue mass. Mass lesions in the left kidney and area of the head of the pancreas were d e m o n s t r a t e d (Figs. 2 and 3).A biopsy o f the lesion in the left innominate bone was performed. R a d i a t i o n therapy was given to the area of this lesion. Subsequently, jaundice, ascites and swelling of b o t h testes developed.