Melanin concentrating hormone. III. Melanin concentrating hormone (MCH): the message sequence

Melanin concentrating hormone (MCH) is a heptadecapeptide synthesized by the hypothalamus and secreted by the neurohypophysis of the teleost pituitary gland. MCH stimulates melanosome aggregation within teleost melanocytes but also exhibits MSH-like (melanosome dispersing) activity on tetrapod (frog and lizard) melanocytes. We have synthesized a number of MCH analogues to determine the essential features of the primary structure necessary to stimulate either melanosome aggregation or dispersion in fish or tetrapod melanocytes, respectively. An analysis of the potencies and actions of these analogues on vertebrate melanocytes is provided and demonstrates that the two activities have different structural requirements.     

Pummerer Rearrangement of Selenium-Containing Uracil Nucleosides

Abstract

Pummerer-type rearrangement of uracil nucleosides having a phenylseleno group in the 2′-, 3′-, and 5′-positions took place upon oxidation with MCPBA in CH₂Cl₂ followed by treatment with acid anhydrides to yield α-acyloxyselenides.     

Subcellular distribution of hydrolase in germinating pea cotyledons

The subcellular distribution of hydrolases in germinating peacotyledons was investigated by differential and sucrose densitygradient centrifugations. Acid phosphatase was present in atleast two kinds of subcellular components. One was slightlyheavier than mitochondria, and the other was so light that itremained on the upper part of the gradient after sucrose densitygradient centrifugation. Protease was localized in the smooth-surfacedmicrosomal fraction which contained antimycin A-insensitiveNADH₂-cytochrome c reductase and no RNA. Aryl esterase existedin a soluble form in the cytoplasm. (Received July 22, 1971; )     

Hopenol-b,a triterpene alcohol from Euphorbia supina

In addition to the known triterpene motiol, hopenol-b (hop-22(29)-en-3β-ol) was isolated from the whole herb of Euphorbia supina. It has not been found previously in nature, though it has been prepared by both synthetic and biosynthetic methods.     

Presence of pepsinogens immunoreactive to anti-embryonic chicken pepsinogen antiserum in fish stomachs: possible ancestor molecules of chymosin of higher vertebrates

1. Stomachs of adult teleosts and elasmobranchs reacted to an anti-embryonic chicken pepsinogen antiserum (anti-ECPg) as well as to an anti-adult chicken pepsinogen antiserum (anti-ACPg). 2. Zymograms and immunoblots of stomach extracts revealed that anti-ECPg- and anti-ACPg-reactive substances possess peptic activity. 3. The possible relationship between anti-ECPg-reactive pepsinogens in fish and prochymosins in higher vertebrates is discussed.     

Replication of X chromosomes in complete moles

Summary DNA replication patterns of X chromosomes in complete hydatidiform moles were studied using cultured fibroblasts from three 46,XX moles resulting from duplication of a haploid sperm, and from a 46,XY mole originating from dispermy. Control cultures included skin fibroblasts from an adult woman and a female fetus as well as PB lymphocytes from an adult woman. Cultures were treated with 5-bromodeoxyuridine for the last 2–4h of the S phase, and the chromosome slides prepared were stained by the Hoechst 33258-Giemsa procedure. Each of the three XX moles studied revealed one early-replicating and one late-replicating X chromosomes, while the XY mole revealed one early-replicating X chromosome. DNA replication patterns of molar X chromosomes were similar to those of adult and fetal fibroblasts, but different from those in adult lymphocytes. These findings indicate that DNA replication kinetics of molar fibroblasts are tissue-specific rather than origin- or developmental-stage specific.     

Phylogenetic analysis of a novel sulfate-reducing magnetic bacterium, RS-1, demonstrates its membership of the δ-Proteobacteria

Abstract Most of the 16S ribosomal RNA gene of a sulfate-reducing magnetic bacterium, RS-1, was sequenced, and phylogenetic analysis was carried out. The results suggest that RS-1 is a member of the δ-Proteobacteria, and it appears to represent a new genus. RS-1 is the first bacterium reported outside the α-Proteobacteria that contains magnetite inclusions. RS-1 therefore disrupts the correlation between the α-Proteobacteria and possession of magnetite inclusions, and that between the δ-Proteobacteria and possession of greigite inclusions. The existence of RS-1 also suggests that intracellular magnetite biomineralization is of multiple evolutionary origins.