Conserved and Variant Molecular and Functional Features of Multiple Egg Yolk Precursor Proteins (Vitellogenins) in White Perch (Morone americana) and other Teleosts

Abstract

Three complete cDNAs encoding different forms of vitellogenin (Vtg) were isolated from a white perch (Morone americana) liver cDNA library and characterized with respect to immunobiochemical and functional features of the three Vtgs and their product yolk proteins (YPs) in this species and in the congeneric striped bass (Morone saxatilis). The two longest cDNAs encoded Vtgs with a complete suite of yolk protein domains that, based on comparisons with vtg sequences from other species, were categorized as VtgAa and VtgAb using the current nomenclature for multiple teleost Vtgs. The shorter cDNA encoded a Vtg that lacked a phosvitin domain, had a shortened C-terminus, and was categorized as VtgC. Mapping of peptide sequences from the purified Vtgs and their derived YPs to Vtg sequences deduced from the cDNAs definitively identified the white perch VtgAa, VtgAb, and VtgC proteins. Detailed comparisons of the primary structures of each Vtg with partial or complete sequences of Morone yolk proteins or of Vtgs from other fishes revealed conserved and variant structural elements of teleost Vtgs with functional significance, including, as examples, signal peptide cleavage sites, dimerization sites, cathepsin D protease recognition sites, and receptor-binding domains. These comparisons also yielded an interim revision of the classification scheme for multiple teleost Vtgs.

Lrp13 is a novel vertebrate lipoprotein receptor that binds vitellogenins in teleost fishes

“…The VtgAa/b intensely appears at 165-177 kDa in the gel, near the molecular mass of VtgAa and the VtgAb monomer ( 16,30 ).…”

“…Aliquots of solubilized ovary membrane proteins, affi nity purifi ed Vtgrs, and purifi ed VtgAa/b were processed for LC-ESI-MS/MS using an LTQ linear ion trap mass spectrometer (Thermo, San Jose, CA) at the NCSU Genomic Sciences Laboratory (Raleigh, NC). Samples were analyzed in quadruplicate and ion fragmentation spectra were queried by MASCOT (Matrix Science, Boston, MA) against white perch VtgAa, VtgAb, VtgC ( 16 ), white perch Lr8 Ϫ ( 18 ), and the translated striped bass ovary transcriptome ( 24,25 ).…”

“…All DNA oligos were designed with Mac Vector (Accelrys Software, San Diego, CA) and obtained from Integrated DNA Technologies (Coralville, IA). Products were cloned from a Stratagene Uni-Zap XR cDNA library (La Jolla, CA) constructed from pooled white perch ovaries ( 18 ), and those from four colonies were bi-directionally sequenced according to our prior studies ( 16 ). Total RNA was extracted from pooled white perch ovaries using TRIzol reagent (Invitrogen, Carlsbad, CA) ( 25 ) and 3 ′ and 5 ′ rapid amplifi cation of cDNA ends (RACE) were performed using FirstChoice RLM-RACE kit (Ambion).…”

Biochemical and Immunochemical Characterization of Two Discrete Vitellogenin Proteins and Their Derived Lipovitellins in the Inshore Hagfish (Eptatretus burgeri)

“…In recent years, a new "multiple Vtg model" has been proposed to describe vitellogenesis in teleosts based on the structural diversity of Vtg Finn and Kristoffersen, 2007;Reading et al, 2009); typically, three kinds of vtg cDNA (i.e., vtgAa, vtgAb, and vtgC) are found in a variety of highly evolved teleosts. Of the teleosts presenting three vtg transcripts, all corresponding Vtg proteins (VtgAa, VtgAb, and VtgC) have been identified in some species, including white perch, Morone americana (Hiramatsu et al, 2002c), mosquitofish, Gambusia affinis (Sawaguchi et al, 2005), red seabream, Pagrus major (Sawaguchi et al, 2006), and grey mullet, Mugil cephalus (Amano et al, 2007a).…”

Evaluation of the Estrogenic and Osmoregulatory Impacts Of Exposure to 4-Nonylphenol Pollution in the Estuarine Arrow Goby, Clevelandia Ios

“…Most teleost fishes have evolved at least three forms of Vtg proteins with each protein encoded by one or more genes: vtgAa and vtgAb encode full length Vtg proteins, while the vtgC gene encodes a truncated Vtg lacking three yolk protein domains (Finn and Kristoffersen, 2007;Reading et al 2009;Reading and Sullivan 2011;Wang et al, 2005;Williams et al, 2014;Yilmaz et al, 2015). The relative expression levels of these genes and, subsequently, proportional composition of yolk proteins derived from the different forms of vtgs varies among fish taxa (Williams et al, 2014).…”