Artificial insemination is widely used in many cattle breeding programs. Semen samples of breeding bulls are collected and closely examined immediately after collection at artificial insemination centers. Only ejaculates without anomalous findings are retained for artificial insemination. Although morphological aberrations of the spermatozoa are a frequent reason for discarding ejaculates, the genetic determinants underlying poor semen quality are scarcely understood.
A tail stump sperm defect was observed in three bulls of the Swedish Red cattle breed. The spermatozoa of affected bulls were immotile because of severely disorganized tails indicating disturbed spermatogenesis. We genotyped three affected bulls and 18 unaffected male half-sibs at 46,035 SNPs and performed homozygosity mapping to map the fertility disorder to an 8.42 Mb interval on bovine chromosome 13. The analysis of whole-genome re-sequencing data of an affected bull and 300 unaffected animals from eleven cattle breeds other than Swedish Red revealed a 1 bp deletion (Chr13: 24,301,425 bp, ss1815612719) in the eleventh exon of the armadillo repeat containing 3-encoding gene (ARMC3) that was compatible with the supposed recessive mode of inheritance. The deletion is expected to alter the reading frame and to induce premature translation termination (p.A451fs26). The mutated protein is shortened by 401 amino acids (46 %) and lacks domains that are likely essential for normal protein function.
We report the phenotypic and genetic characterization of a sterilizing tail stump sperm defect in the Swedish Red cattle breed. Exploiting high-density genotypes and massive re-sequencing data enabled us to identify the most likely causal mutation for the fertility disorder in bovine ARMC3. Our results provide the basis for monitoring the mutated variant in the Swedish Red cattle population and for the early identification of infertile animals.
In 1971 it was discovered that the nine-banded armadillo (Dasypus novemcinctus) could be infected in the laboratory with Mycobacterium leprae, and would manifest disease similar to the lepromatous form of leprosy in man. In 1975 several wild armadillos captured in Louisiana were found to have a disease identical to the M. laprae infection in laboratory animals. To determine if there is a significant association between contact with armadillos and presence of leprosy in humans, the armadillo contact of persons with indigenous leprosy in Louisiana was compared to the contact of matched controls. No difference in the nature or frequency of contact was found. If this infection of wild armadillos is of recent onset, an association with human leprosy in enzootic areas may not be detectable for several years.
Northern Louisiana has been essentially free of indigenous leprosy, and now it is not. Six new cases of leprosy have been diagnosed: three in 1986, the other three in 1985, 1983, and 1982, respectively. The patients had been lifelong residents of six scattered rural parishes. Leprosy had never been reported from five of them. No patient had had contact with human leprosy. The patients were white; four were women; the mean +/- SD age at onset was 60.3 +/- 16.4 years (age range, 31 to 80 years); and the mean +/- SD interval to diagnosis was 1.2 +/- 1.4 years. One patient had Hodgkin's disease at the age of 25 years and leprosy at the age of 31 years; another patient had cervical carcinoma. All rural northern Louisiana residents coexist with armadillos (Dasypus novemcinctus), some of which are infected with Mycobacterium leprae, the significance of which is unknown. Hypothetically, exposure to an unknown human case, reactivation of "asymptomatic" leprosy through immunosenescence or immunosuppression, or infection from an environmental source might have occurred. Because the patients lacked contact, travel, residence, and exposure risk factors, the origin of leprosy in the new indigenous cases is noteworthy and is not understood.
In the period 1971-1981, 1,835 cases of leprosy were reported in the United States; only 10% of these cases were indigenous. Since 1977, the number of new cases reported each year has risen because of an increase in imported cases of disease, a situation reflecting the increased number of refugees and immigrants who have entered the United States from areas endemic for leprosy. Forty-five of the 50 states reported cases. In only 25% of the imported cases were the patients known to have had leprosy at the time of immigration; the remaining 75% were diagnosed in this country. The highest rate of disease onset for this latter group occurred within 12 months after entry into the United States, but cases continued to be reported 10 years after entry. Active refugee resettlement programs have widely distributed persons with leprosy, contacts of diseased persons, and persons from endemic areas throughout the 50 states, a situation necessitating the development of expertise by medical professionals and public health officials in the diagnosis, treatment, and long-term follow-up of patients with leprosy.
A trial with a candidate anti-leprosy vaccine based on killed Mycobacterium leprae was started in Norway in 1983 to evaluate its toxicity and efficacy to induce cell-mediated immunity (CMI) in BCG-vaccinated healthy volunteers. The vaccinated subjects were found to be free of unacceptable side-effects and their T cells showed elevated proliferative response to M. leprae up to 1 year postvaccination. When tested in 1991, 8 years after vaccination, peripheral blood mononuclear cells from the same volunteers showed a persistent high proliferative response to M. leprae. From a total of 147 T-cell clones established from these subjects, 26 clones were specific to M. leprae and the remaining T-cell clones responded to M. leprae as well as to BCG and other cultivable mycobacteria. The epitopes recognized by the M. leprae-specific T-cell clones were present on several protein antigens including the 18 kDa and the 65 kDa heat shock proteins. A dominant epitope, peptides 38-50 on the M. leprae 18 kDa heat shock protein, which was recognized by M. leprae-specific T cells 1 year after vaccination, was also recognized 8 years after vaccination by the same donor. This is the first report demonstrating the unique property of killed M. leprae with respect to the induction of long-lasting T-cell reactivity towards M. leprae antigens in humans.
Three native-born patients from the Mississippi Delta presented with leprosy over a 13-month period. None had a history of foreign travel, contact with each other, or known leprosy patients. Two patients' lesions lacked anesthesia, and all had a history of armadillo exposure. These cases add to the association of armadillo exposure and the subsequent development of leprosy.
Comment In: South Med J. 2008 Jun;101(6):58318475232
Thirty U.S. Trypanosoma cruzi stocks isolated mainly from wild mammals were characterized by multilocus enzyme electrophoresis at 22 genetic loci and random amplification of polymorphic DNA for 10 primers. Two main phylogenetic clusters, separated by large genetic distances, were discriminated by both methods, corresponding, respectively, to the formerly described zymodemes I and III. Two stocks isolated from indigenous human cases were identified as zymodeme I. Genetic diversity of the U.S. T. cruzi isolates was considerable, comparable to that scored in similarly sized samples from South America. These results favor the hypothesis that T. cruzi U.S. stocks were not imported at a historical time and are indigenous to the native fauna of the United States. The population structure of these stocks appeared to be basically clonal, as previously reported in South America, and no evidence of hybrid genotypes was found in the United States.