Phylogeny and regulation of four lipocalin genes clustered in the chicken genome: evidence of a functional diversification after gene duplication

Lipocalins – a family portrait

“…The ancestor protein of E-RABP could be a L-PGDS-like protein, and events causing changes in properties of descendant lipocalins are related to environmental pressure after emergence of internal insemination by amniota in the course of evolution (Suzuki et al, 2004). As noted previously, chondrogenesis-related lipocalin genes (Ex-FABP, CALb, CALg and Ggal-C8G8), grouped in a cluster are monophyletic and related to a-1-microglobulin, C8G8, L-PGDS and NGAL (Pagano et al, 2004). Most of the human lipocalins (a1-acid glycoprotein, a1-microglobulin, glycodelin, NGAL, C8G8) are found in the 32-34 stripe of chromosome 9, long arm: 9q.…”

“…Ggal-C8G8 is expressed in the liver, kidney, brain, heart, skeletal muscles, and particularly in the skin. However, it is not expressed during chondrocite differentiation; thus, its function must be different from the other CAL protein (Pagano et al, 2004).…”

Zebrafish and chicken lipocalin-type prostaglandin D synthase homologues: Conservation of mammalian gene structure and binding ability for lipophilic molecules, and difference in expression profile and enzyme activity

“…In contrast, some lipocalin genes were found to be clustered in human and mouse chromosomes (Salier, 2000). Recently, Pagano et al (2004) reported that chicken lipocalin genes were also clustered. Mammalian and non-mammalian lipocalin genes including the L-PGDS gene are thus clustered, and the C8γ gene is a neighbor of the L-PGDS gene in all mammalian and non-mammalian species identified up to now.…”

Specific Roles of the iroBCDEN Genes in Virulence of an Avian Pathogenic Escherichia coli O78 Strain and in Production of Salmochelins

“…In the avian host, it is clear from our study that the enterobactin system alone is insufficient for APEC virulence, and it is thus probable that an avian host defense protein akin to NGAL plays a similar role in protection against enterobactin-mediated iron acquisition. A number of different chicken lipocalins which have been shown to be upregulated during inflammation or in response to bacterial signaling molecules have been identified (41), and one of these may have a protective role against enterobactin-mediated bacterial iron acquisition. However, as demonstrated in the present work, the salmochelin-siderophore system, comprised of functional synthesis, export, import, and processing components encoded on the iro gene cluster, is efficient at circumventing any avian innate host defenses that may respond to or sequester enterobactin.…”