Cloning of a Syrian hamster cDNA related to sexual dimorphism: establishment of a new family of proteins

Abstract

The clone FHG22, isolated from a female minus male subtracted cDNA library obtained from the sexually dimorphic Syrian hamster Harderian glands (HG) is 440 bp long with a 95 amino acids ORF, and hybridizes to a female HG-specific 0.6 kb mRNA. The FHG22 nucleotide and amino acid sequences are similar to the subunits from prostatein, uteroglobin, major cat allergen Fel dI (chain 1) and mouse salivary androgen binding proteins (subunit o 0. Therefore I propose that all those polypeptides belong to a common new family. The hamster genome has a single copy of the FHG22 gene, without homologous genes. FHG22 mRNA is also found in male and female parotid (higher levels in females) and submandibular glands, indicating a tissue and sex-dependent control of expression.

Characterization and Cloning of Two Isoforms of Heteroglobin, a Novel Heterodimeric Glycoprotein of the Secretoglobin-Uteroglobin Family Showing Tissue-specific and Sex Differential Expression

“…As reflected in Fig. 1C, it exactly matches residues 22-33 of the ORF found in the FHG22 cDNA, thereby demonstrating that the predicted signal peptidase cleavage site was correct (3,53) and identifying the HGB.A polypeptide as the mature product of FHG22 mRNA. A doubt as to its positive identification could be raised by the clear difference observed between the cDNA-deduced size of the mature product (M r 8,196) and that measured by SDS-PAGE (M r 5,600).…”

“…RNA Preparation and Northern Analysis-RNA was extracted as previously described (3,41) from the following male and female hamster tissues: spleen, brain, liver, small intestine, pancreas, lung, kidney, heart, thymus, adrenal gland, harderian gland, parotid gland, and submaxillary gland and also from ovary, uterus, prostate, seminal vesicle, and testes. Concentration, purity, and integrity of the RNA samples were assessed by A 260/280 measurement and agarose electrophoresis.…”

“…The existence of a uteroglobin/Clara cell 10-kDa family of proteins including UGB/CC10 orthologs and paralogs (such as subunits of rat prostatein, cat Fel d 1 and mouse androgenbinding protein, and cDNAs like hamster FHG22) was previously suggested (1)(2)(3)(4). New related proteins and cDNAs were described (5)(6)(7)(8)(9), and the family was formally established during a meeting in which a nomenclature committee (10) coined the generic name of secretoglobins (SCGBs).…”

“…We had previously prepared two sex-differential cDNA libraries and isolated male-and female-specific clones (3,37) from Syrian hamster harderian glands. These are secretory organs from the orbital cavity related to the pineal gland and the gonads (38,39), which in hamster show reversible sexual dimorphism regulated by hormones and other factors (40 -42).…”

“…These are secretory organs from the orbital cavity related to the pineal gland and the gonads (38,39), which in hamster show reversible sexual dimorphism regulated by hormones and other factors (40 -42). The female harderian gland cDNA clone FHG22 was characterized in our laboratory and related to the UGB family as mentioned (3). The FHG22 mRNA was found to be expressed according to a tissueand sex-specific pattern (3) only in three hamster exocrine glands; the highest levels are observed in parotid glands from either sex, and FHG 22 mRNA is present in female but not in male harderian glands and presents higher expression levels in female than in male submaxillary glands.…”