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At least 37 records · Page 2Linked to original sources
PubMed1979

Hybrid pigment organelles in an invertebrate.

Observations of a number of vertebrate chromatophores have revealed the presence of more than one type of pigment organelles, suggesting that the different types are all derived from an equipotential organelle able to differentiate into any of the major pigment-containing organelles (Bagnara, 1972). Observations are presented concerning the occurrence of hybrid pigment inclusions, i.e., all kinds of intergrades between melanosomes, pterinosomes, and reflecting platelets in pigment cells of the daddy-long-legs. It therefore seems possible that pigment organelles in some invertebrates may also be derived from a common pluripotential primordial organelle.

Animals↗
PubMed1979

The relation of radiation sensitivity to pronuclear chromosome structure. II. Differences in radiation sensitivty between two stocks of Phryne cincta characterized by low or high crossing-over frequency.

After treatment of spermatozoa of Phryne cincta from a Berlin population (bs) with low crossing-over and from an Alpine population (as) with high crossing-over frequency, egg mortality was ascertained and chromosomal mutation rate determined by examination of the polytene chromosomes of the F1 progeny. - The as stock exhibits a 1.33 times greater radiation sensitivity than the bs stock, both in chromosomal mutation and in egg mortality rates. There is no evidence that factors other than structural ones account for the differences in radiation sensitivity. From inversion length measurements, it was proposed that a reduction of the spiral diameter of the paternal pronucleus chromosomes is responsible for a higher site number and thereby for a greater radiation sensitivity.

Animals↗
PubMed1976

The stoichiometry of the components of arthropod thin filaments.

Limulus thin filaments confer calcium sensitivity on calcium-independent myosins and contain in addition to actin and tropomyosin, three troponin components. The molar ratio of actin:tropomyosin:troponin sub-unit T (TN-T): troponin sub-unit C (TN-C) is approximately 7:1:1:1, as in vertebrates, but twice the amount of the troponin sub-unit I (TN-I) may be present. Arthropod troponin binds approximately 1 mole Ca/mol troponin, a significantly smaller amount than bound by vertebrate troponin.

Actins↗