Histology of the suprapubic and anogenital cutaneous glands in male cotton top tamarins (Saguinus oedipus).

In cotton top tamarins (Saguinus oedipus), scent glands have been mostly studied in females from museum collections. This work aims to extend the investigation to male specimens, introducing a novel source of skin samples. Two adult males from zoo populations, one intact and one castrated, were immediately frozen after natural death. Skin samples were later collected at the thawing onset, soaked with cold fixative and processed for light microscopy. Sebaceous units of scent glands showed phasic secretory activity in the intact male and marked fibrosis in the castrated male. It appears, therefore, that light microscopy samples from frozen tissues provide detailed features that can disclose distinctive traits in specimens characterized by different hormonal balances.

Skin of the Red Eye Tree Frog Agalychnis Callidryas (Hylidae, Phyllomedusinae) Contains Lipid Glands of the Type Described in the Genus Phyllomedusa.

Several anuran species of the genus Phyllomedusa are known to possess specialized cutaneous glands producing lipids and exhibit a peculiar wiping behavior. This behavior is a stereotyped repertory of fore and hind limb movements distributing hydrophobic molecules onto the body surface and reducing evaporative water loss. No reports are presently available on the occurrence of lipid glands in other phyllomedusine genera, and data on the structure of the secretory units specialized for the production of cutaneous lipids are still unclear. The present report is aimed to answer both questions: it describes lipid glands of the Phyllomedusa type in Agalychnis callidryas and provides light and transmission electron microscope evidence of the syncytial structure of their secretory units, a typical feature of serous glands in anuran skin. This morphological trait supports the hypothesis that lipid glands are a specialized subset of the anuran serous glands, and underlines their flexible role in the skin adaption to sub-aerial environments. Anat Rec, 300:503-506, 2017. © 2016 Wiley Periodicals, Inc.

Larval epidermis of the red eye tree frog Agalychnis callidryas (Anura, Hylidae): ultrastructural investigation on the Kugelzellen, specialized forms of the constitutive skein cell line.

An ultrastructural study was carried out on the epidermis of Agalychnis callidryas tadpoles during limb development. Larval epidermis consisted of four cell layers: basal, lower intermediate, upper intermediate, and surface or apical layers. Basal cells represented the stem compartment of intermediate cells: both belong to the skein cell (SC) lineage, described in several anuran species, on account of the conspicuous intracytoplasmic tonofilament bundles. Apical cells were secretory in nature and released mucus on the body surface. Intermediate SCs exhibited a hydrated central cytoplasm and peripheral tonofilament bundles. They closely resembled the epidermal ball-like cells, Kugelzellen (KZn) of Xenopus laevis tadpoles, and possibly shared their turgor-stiffness properties. In A. callidryas, the stratification of intermediated SCs on their stem cell layer provided the chance to study their cytodifferentiation in a suitable sequence, until basal cell differentiation shifted toward the keratinocyte lineage in premetamorphic stages. Present data assign A. callidryas to the anuran species with a constitutive SC population in larval epidermis, and demonstrate that KZn express the ultimate specialization of such cell line. SCs were arranged in the fashion of a random-rubble stone groundwork, and possessed long processes. These cytoplasmic outgrowths contained a tonofilament axial rod and held together contiguous cells. Ultrastructural findings suggest that this complex structure may impart compressive as well as sliding strengths to the larval epidermis, representing a possible adaption to the fresh water environment.