The IUCN lists the Snow Mountain Mannikin as having a stable population, but that is something of a guess. What really stands out about this bird is how little we know about it. The genus name, Lonchura, refers to the pointed tail feathers of some members of the group. It is a perfectly respectable little songbird with a black face, light brown bib, darker brown back, striped sides, and a robust grey bill suitable for cracking small seeds. The Snow Mountain Mannikin was unknown to the bird world until 1939, when it was found at an elevation of more than four thousand metres in the Snow Mountains of west-central New Guinea. The species name, ardens, is Latin for glowing or burning, likely a reference to the males’ bright red collar. The genus name, Euplectes, refers to their woven nest. Males and females both contribute to nest building, but incubation and feeding of nestlings are carried out by the females alone. Males with the longest tails attract two or three mates, while more poorly-ornamented males remain unmated. Most impressive is the male’s black tail, which is longer than the rest of the bird in some subspecies. Some are all black, but most have a bright red slash across their throat. Roughly twice the size of a flowerpecker, female Red-collared Widowbirds are nondescript in their colouration. This bird has a wide, but patchy distribution across the southern half of Africa, and it is known to occupy a wide range of habitats. The scholarly community has known about the Red-collared Widowbird since the late 18th century. Even though we know almost nothing about the breeding biology of this species, the International Union for the Conservation of Nature considers the Merida Flowerpecker to be of least concern. The genus name, Diglossa implies that the bird has two tongues or has two voices, while the species name, gloriosa, is the Latin form of the word glorious. Both males and females are mostly black or blueish-grey on top, with reddish-brown undersides. Like hummingbirds, this flowerpecker feeds mainly on nectar and small insects. A teeny songbird, it is sometimes displaced from good foraging spots by hummingbirds. It can be found in the scrubby highlands of the Mérida region of Venezuela. The Merida Flowerpecker was discovered in 1871. Scale bars: 20 μm.Painting of a Merida Flowerpecker by Joseph Smit – Proceedings of the Zoological Society of London (vol. Cells expressing mGPIHBP1-W108S did not bind cLPL-wt. ( B) Immunocytochemistry studies showing that cLPL-wt bound avidly to CHO cells expressing wild-type mGPIHBP1 (colocalization), while LPL-C420Y had no capacity to bind to cells expressing wild-type mGPIHBP1 (no colocalization). Cells expressing hGPIHBP1-W109S did not bind cLPL-wt. ( A) Immunocytochemistry studies showing that cLPL-wt bound avidly to neighboring CHO cells expressing wild-type hGPIHBP1 (hence cLPL-wt colocalized with hGPIHBP1), whereas cLPL-C420Y had no capacity to bind to cells expressing wild-type hGPIHBP1 (no colocalization). Immunocytochemistry studies were performed on permeabilized and nonpermeabilized cells with a goat antibody against the S-protein tag (red) and a mouse monoclonal antibody against the V5 tag (green). We conclude that LPL reaches the capillary lumen in chickens - as it does in mammals - despite an apparent absence of GPIHBP1.ĬHO pgsA-745 cells were transiently transfected with S-protein–tagged wild-type human (h) or mouse (m) GPIHBP1 (or hGPIHBP1-W109S or mGPIHBP1-W108S) and coplated with cells that had been transfected with V5-tagged versions of cLPL (wt or C420Y). However, we could not identify a gene for GPIHBP1 in the chicken genome, nor could we identify a transcript for GPIHBP1 in a large chicken RNA-seq data set. Remarkably, chicken LPL bound in a specific fashion to mammalian GPIHBP1. LPL was released rapidly from chicken hearts with an infusion of heparin, consistent with LPL being located inside blood vessels. When the antibodies against chicken LPL were injected intravenously into chickens, they bound to LPL on the luminal surface of capillaries in heart and adipose tissue. Using purified antibodies against chicken LPL, we showed that LPL is present on capillary endothelial cells of chicken heart and adipose tissue, colocalizing with von Willebrand factor. The obvious question is whether the LPL in lower vertebrates is able to reach the capillary lumen. In all lower vertebrate species (e.g., birds, amphibians, reptiles, fish), a gene for LPL can be found easily, but a gene for GPIHBP1 has never been found. In mammals, GPIHBP1 is absolutely essential for transporting lipoprotein lipase (LPL) to the lumen of capillaries, where it hydrolyzes the triglycerides in triglyceride-rich lipoproteins.
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