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Biomedical subjects

U A Heinlein

Publications and source records attributed to U A Heinlein.

27 records · Page 2Linked to original sources

High-level expression in male germ cells of murine P68 RNA helicase mRNA.

The complete cDNA coding for mouse P68 RNA helicase was cloned and its nucleotide sequence was determined. The sequence is about 95% identical to the human equivalent. Whereas the 5'-untranslated region is less conserved (71%), the 3'-ends of mouse and human mRNAs are nearly identical. Between stop codon and poly(A)-tail both sequences are 97% conserved. At the level of amino acid sequence, the similarity of both, mouse and human, DEAD box family proteins is as high as 98%. In situ hybridizations using cDNA subfragments as probes revealed a testis-selective expression of P68 RNA helicase mRNA. The signal was restricted to late pachytene spermatocytes and haploid spermatids. Northern blot analyses corroborated these results but suggested that expression of related mRNA species occurs in a variety of other tissues.

Amino Acid Sequence↗

Characterization by enriched polyclonal antibodies of developmentally regulated and cell type specific mouse testis antigens.

Polyclonal antisera directed against testicular proteins were characterized by immunocytochemistry and Western blot analysis. Antibodies binding to testis-specific, developmentally regulated protein bands were eluted from their antigens and used for further characterization of the developmental profile and cell type-specific expression of two antigens, PSM33 and NNA75. While PSM33 was found to be present in spermatocytes from the late pachytene stage on, NNA75 could be localized in neonatal interstitial cells. NNA75 expression ceases by to postnatal day ten, when first meiosis starts within the seminiferous tubules, thus suggesting an interactive role of Leydig cells during the onset of meiotic divisions.

Animals↗

Detection of secreted and temporarily inducible heat shock responsive proteins in mouse testicular tissue.

Temperature-induced effects on the synthesis of murine testicular proteins were investigated by one- and two-dimensional SDS polyacrylamide gel electrophoresis. Newly synthesized proteins were monitored by incorporation of 35S-methionine and autoradiography. Three heat shock responsive proteins, which are differently affected by elevated temperatures, are described. These proteins represent special examples for how testicular cells respond to environmental stress. One of these proteins, HSl36, is synthesized and secreted at 38 degrees C, whereas at lower, scrotal temperatures it is not detectable. HSlD74 protein is synthesized at elevated temperatures, but only in prepuberal testis, not in adult. Synthesis of the third example, HSR28, is decreased within the seminiferous tubules, but only in those regions which bear cell associations of the elongation stage. These results indicate that the use of DNA probes of the 'heat shock'-gene family might not be sufficient to describe the molecular reasons for impaired spermatogenesis following hyperthermia.

Aging↗

Staggerer-specific protein SP47: a unique species among age- and genotype-dependent cerebellar proteins.

Genotype- and age-specific proteins are found in the developing cerebellum of wildtype and staggerer (sg/sg) mutant mice by analysis of silver-stained one- and two-dimensional protein patterns. The methods used are suitable for gross inspection of protein patterns without previous purification, labeling, or immunochemistry. SP47, a polypeptide of 47 kD with a pI of 6.0, appears in the mature staggerer cerebellum, but not in the wildtype. SP47 is different from the astrocytic glial fibrillary acidic protein (GFAP) as shown by immunoblotting. Four polypeptides have been identified with distinct development- and genotype-dependent patterns in the cerebellum. Some of the changes are correlated with events during postnatal histogenesis.

Aging↗

A highly abundant transcript in adult murine cerebellar granule cells contains repetitive sequences homologous to L1.

Cloned cDNA from adult mouse cerebellum composed of subsequences homologous to the L1Md consensus sequence (long interspersed repetitive element "LINE" family of the mouse) hybridizes specifically with large nuclear poly(A)+RNAs that are highly concentrated in the murine and rat cerebellum. These homogeneous L1-related transcripts were localized in the mouse CNS by in situ hybridization with 3H- and biotin-labeled DNA probes. They were found to hybridize to cerebellar granule cells specifically.

Animals↗

Molecular characterization of the MT-family of dispersed middle-repetitive DNA in rodent genomes.

We report the consensus sequence of members of a new dispersed middle-repetitive DNA family, MT, which is present in mouse and rat genomes. This family is shown to be as abundant as the described rodent B1 and B2 families. Hybridization experiments with radioactive single-stranded cDNAs from different tissues indicate that MT sequences are more abundantly cotranscribed in parts of the brain than other repetitive families.

Animals↗

Development-dependent regulation of N-acetyl-beta-D-hexosaminidase of cerebellum and cerebrum of normal and staggerer mutant mice.

Distinctive activities of various glycosidases were expressed in the cerebellum and cerebral cortex of mice during their development. In particular, N-acetyl-beta-D-hexosaminidase (EC 3.2.1.30) appeared to be developmentally regulated. A transient peak of enzyme activity at postnatal day 7 was characteristic for the cerebellum, whereas the activity in the cerebral cortex gradually increased through the 1st postnatal month and was maintained at a high level of activity throughout adulthood. The regulation of N-acetylhexosaminidase activity in the developing cerebellum of the staggerer mouse deviated clearly from enzyme activities in the wild-type, whereas the activity pattern in the staggerer cerebral cortex remained unaffected. In experiments mixing wild-type and staggerer cerebellum homogenates, the specific activity was additive. Thus, involvement of inhibitors or activating molecules can be excluded. This developmentally controlled regulation or disregulation in staggerer appears to be enzyme specific, sine beta-glucosidase, alpha-glucosidase, and beta-galactosidase did not exhibit such a pattern in either normal or staggerer mice. In the mutation weaver that, like staggerer, loses the majority of its cerebellar granule cells, N-acetyl-beta-hexosaminidase activity of the cerebellum was not elevated, indicating a specific defect in staggerer rather than a general effect on lysosomal enzymes due to cell death.

Aging↗