The skin of primates. XXXVI. The skin of the pigmy marmoset--Callithrix (Cebuella) pygmae

The pigmy marmoset — Callithrix (= Cebuella) pygmaea Spix — is the second detailed study of the members of the family Callithricidae. It is closely allied to the red-mantled tamarin — Saguinus (=Tamarinus) fuscicollis illigeri Spix — and shares some of its characteristics with both Prosimii and Anthropoidea. The epidermis and dermis contain moderate numbers of concurrent, melanotic melanocytes. The dermis is rich in elastin. Hair follicles grow in groups of three or four over the general body surface, and one apocrine gland is associated with each grouping. Arrectores pilorum muscles are well developed. On the ventral ulnar wrist are sinus hairs associated with apocrine glands. Most hair follicles have nerve end-organs around them that are reactive for acetylcholinesterase and alkaline phosphatase. There is a large aggregation of sebaceous glands in the suprapubic region. The large sebaceous glands in the eyelid, face, and external genitalia are surrounded by cholinesterasereactive nerves. Apocrine glands are found over most of the hairy skin except the brow, scalp and back; a large grouping of them is present in the sternal region. Only the secretory coils of apocrine glands in the external genitalia are invested with butyrylcholinesterase-rich nerves. Eccrine glands are confined to the volar surfaces of the pes and manus. They have dark cells with abundant glycogen and clear cells with neither glycogen nor PAS-reactive material. The nerves around the eccrine secretory coil are reactive only for acetylcholinesterase.     

The skin of primates. XXXIV. The skin of the golden spider monkey (Ateles geoffroyi)

The skin of the golden spider monkey (Ateles geoffroyi) has many histological and histochemical similarities to that of the woolly monkey (Lagothrix lagotricha) and howler monkey (Alouatta caraya); however, this monkey possesses certain peculiar properties such as large sebaceous glands, a combined distributional pattern of eccrine and apocrine sweat glands, and abundant alkaline phosphatase in the sebaceous glands, apocrine and eccrine sweat glands. In brief, the anatomical and histochemical properties of the skin of this animal are more similar to those of the howler monkey than to the woolly monkey. In addition, the skin of these three Ceboids falls phylogenetically between that of the Cercopithecoidea and Pithecoidea.     

Crossing over frequency following inbreeding inNeurospora

Crossing over frequency was determined for five marked regions covering most of a chromosome arm. The results of a 12th backcross were compared with previously published results from the noninbred f₁. Exchange frequency increased significantly following inbreeding. Chiasma interference remained positieve, but was somewhat less intense in b₁₂.Supported in part by Public Health Service Research Grants AI 01462 and GM 1882-01, by a National Science Foundation Faculty Fellowship to H. R. C., and by Public Health Service Research Career Award K6-GM-4899 to D. D. P.Technical Paper No. 2054, Oregon Agricultural Experiment Station, Corvallis.     

Platelet-activating factor and serum components from oestrous mice co-operate to mimic the activity of 'early pregnancy factor' in the rosette inhibition assay

When male mouse spleen cells were incubated with a combination of platelet activating factor (PAF, 1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) and sera from female mice in oestrus, the cells displayed a markedly increased rosette inhibition titre (RIT) when subsequently tested in the rosette inhibition assay. Neither PAF nor oestrous mouse sera alone could induce this effect, the combined action was required. Lyso-PAF could not substitute for the PAF, nor could male mouse sera nor the sera from females in dioestrus or metoestrus substitute for the oestrous mouse serum requirement. Pro-oestrous mouse sera could replace oestrous mouse sera but were less effective in their dose-responses. Studies on the mechanism of action of the PAF and oestrous mouse serum components suggested that the PAF stimulated the production and release of soluble factors (termed S2 factors) which by themselves could induce increased RIT values when applied to fresh spleen cells. The PAF-stimulated cell populations were rendered refractory to the action of these S2 factors and did not display increased RIT values, unless oestrous mouse serum was added. This serum acted to reverse the refractory state, allowing the S2 factors to exert their effect, and so cells treated with PAF and oestrous mouse serum displayed increased RIT values.     

Function of the human immunodeficiency virus types 1 and 2 Rev proteins is dependent on their ability to interact with a structured region present in env gene mRNA.

The interaction of the human immunodeficiency virus type 1 (HIV-1) Rev protein with a structured region in env mRNA (the Rev-responsive element [RRE]) mediates the export of structural mRNAs from the nucleus to the cytoplasm. We demonstrated that unlike HIV-1 Rev, which functions with both the HIV-1 and HIV-2 RREs, HIV-2 Rev functions only with the HIV-2 RRE. Rev-RRE binding studies suggested that the lack of nonreciprocal complementation stems from the inability of HIV-2 Rev to interact with HIV-1 RRE RNA. Maintenance of RNA secondary structure, rather than the primary nucleotide sequence, appeared to be the major determinant for interaction of both HIV-1 and HIV-2 Rev with the HIV-2 RRE. Moreover, the binding domain of the HIV-2 RRE recognized by HIV-1 Rev was dissimilar to the binding domain of the HIV-1 RRE, in terms of both secondary structure and primary nucleotide sequence. Our results support the hypothesis that function of HIV Rev proteins and possibly the functionally similar Rex proteins encoded by the human T-cell leukemia viruses (HTLVs) HTLV-I and HTLV-II is controlled by the presence of RNA secondary structure generated within the RRE RNA.     

Flow cytometric competitive binding assay for determination of actinomycin-D concentrations

A single step, separation free competitive binding reaction between the fluorescent antibiotic mithramycin and actinomycin-D for common binding sites on DNA coated 10 microns diameter microspheres is described. The fluorescence of the microspheres is measured with a flowcytometer. In the presence of a constant amount of mithramycin, the microsphere fluorescence is inversely proportional to actinomycin-D concentration.