THE OCCURRENCE OF HISTOCHEMICAL ACTIVITY OF 3ß-HYDROXYSTEROID DEHYDROGENASE IN THE DEVELOPING TESTES OF POECILIA RETICULATA.

In the mature testes of the guppy, Poecilia reticulata, some groups of cells, distributed sparsely in the interspace between the peripheral germ cell layer and the hilar duct system, show evident histochemical response for Δ5 -3ß-hydroxysteroid dehydrogenase (3ß-HSD). In the testis of newly delivered guppies, somatic cells are present in the testicular hilus as a compact mass without revealing any structural differentiation. In the testis of juvenile fish of the 8mm stage about 7 days after birth, interstitial cells resembling histologically those of adult testes become differentiated from the somatic cell mass and, though only in some specimens, coincidentally begin to display weak but obvious histochemical response for 3ß-HSD. Thereafter the occurrence of enzyme activity becomes increasingly regular in the developing testes, and attains the adult pattern of distribution in testes of all specimens after the 11 13mm stage or 17 ∽ 20 days of age. The appearance and enhancement of 3ß-HSD activity in the testis is concurrent with the differentiation and development of the testicular duct system. Treatments of newly delivered fish with methyltestosterone (30 ∽ 50 µg/g diet) distinctly stimulate the development of the duct system, which suggests a possible role of androgen secretion occurring in the early phase of the testicular development in the control of testicular organogenesis in the guppy.

Undiagnosed collecting duct carcinoma presenting as meningeal carcinomatosis and multiple bone metastases.

A 54-year-old woman presented with blepharoptosis, numbness in the lower lip, dysgeusia and pain in the extremities and back. MRI showed marked meningeal thickening and multiple bone lesions accompanying a prominent enhancing effect. CT scan of the chest and abdomen appeared to be unremarkable for primary cancer. She died 3 months after the admission, and postmortem autopsy showed a mass of about 2.5 cm in diameter in the renal medulla. Histological examination including immunohistochemistry confirmed the presence of a collecting duct carcinoma (CDC). This case is of particular interest because it emphasizes the possible fulminate clinical course of a small CDC.

Telomeric fingerprinting of the violet root rot fungus, Helicobasidium mompa: a useful tool for karyotype estimation.

We hybridized the telomere-associated DNA sequence pTel46 isolated from Coprinus cinereus with Helicobasidium mompa genomic DNA. The hybridized fragments were more sensitive to Bal31 nuclease than those that were not hybridized, suggesting that they were located at the ends of chromosomes in H. mompa. The hybridization profile can be used to estimate chromosome number, since the number of chromosomes in a single basidiospore isolate is about half that in putative parent strains. Thus, single basidiospore and field isolates might be homokaryons and heterokaryons respectively. We found telomere-linked restriction fragment length polymorphisms (RFLPs) in strains of H. mompa isolated from field and individual basidiosporcs. Thus, this marker appears to be an excellent tool with which to reveal the considerable polymorphism of H. mompa and to identify strains. The RFLP was not found among several strains of the same mycelial compatibility group (MCG) isolated from the same field, suggesting that strains belonging to an MCG group are identical.

Heterologous diploid nuclei in the violet root rot fungus, Helicobasidium mompa.

Allelic genes hga1-1 and hga1-2, which encode G protein alpha subunit in the violet root rot fungus, Helicobasidium mompa, were sequenced and characterized. Restriction fragment polymorphism (RFLP) analysis determined that the gene is present as a single locus in the single basidiospore isolates, while strain V169 possessed both alleles of this gene. Therefore, although basidiospore isolates are dikaryon, they are homokaryotic. Field-isolated strain V169, the putative parent strain, is a dikaryotic heterokaryon. Allelic genes hga1-1 and hga1-2 segregated in almost a 1:3 ratio among single basidiospore isolates from the same fruiting body. Moreover, the copy number of hga1-1 was found to be less than that of hga1-2 in the V169 strain. These results suggest that one of the nuclei in the V169 parent strain is homozygous diploid and the other heterozygous diploid. This parent strain produced four homokaryotic and dikaryon basidiospores on each basidium.