Purification and characterization of a novel incomplete-type vitellogenin protein (VgC) in Sakhalin taimen (Hucho perryi)

Abstract

A novel, incomplete-type vitellogenin (VgC) and its derived yolk lipovitellin (LvC) were immunologically detected in female serum and egg extracts, respectively, of Sakhalin taimen (Hucho perryi) using a subtype-specific antiserum against LvC of grey mullet (Mugil cephalus). The taimen VgC was purified from the sera of vitellogenic females by a combination of gel filtration, anion exchange, and immunoadsorbent column chromatography. Gel filtration of the purified VgC revealed that it had an apparent native mass of ~380 kDa, while the mass of the VgC polypeptide that appeared following SDS-PAGE was estimated to be ~140 kDa. An antiserum was raised against the purified VgC and utilized for the development of a subtype-specific immunoassay for VgC. Levels of VgC in the serum of female taimen increased from 25 µg/ml to ~1 mg/ml, with an increase of GSI. Levels of complete-type Vg and estradiol-17β (E 2 ) in the serum of E 2 -administered juvenile taimen increased and reached peak levels similar to those found in vitellogenic females. Although VgC could be induced in the serum of E 2 -administered taimen, it stayed at levels (35.5-73 µg/ml) lower than those obtained in females. This is the first report on the presence of serum VgC and yolk LvC in a salmonid species; these findings indicate that for Sakhalin taimen, like other highly-evolved teleost species, this minor subtype of Vg is significant in the formation of egg yolk.

Resolving the complexity of vitellogenins and their receptors in the tetraploid Atlantic salmon (Salmo salar): Ancient origin of the phosvitin‐less VtgC in chondrichthyean fishes

“…Salmonids spawn in freshwater, and their large, benthic eggs contain small amounts of VtgC compared to the abundance of VtgAsa. Sakhalin taimen ( Hucho perryi ) possess VtgAsa‐to‐VtgC ratios of ∼22:1 in serum and vitellogenic yolk (Amano et al, ), while >100 times higher serum levels of VtgAs compared to VtgC were measured in cutthroat trout at late vitellogenesis (Mushirobira et al, ). Correspondingly, ovarian expression of vtgAsa in Atlantic salmon and cutthroat trout peaked before spawning, at about 40 and 140 times higher levels, respectively, than vtgC (Mushirobira et al, ; this study).…”

Vitellogenesis and choriogenesis in fishes

“…In contrast, because VtgC has a lower molecular weight than the other two types, it is relatively easy to purify. To date, the complete Vtg (VtgA and/or VtgB) and incomplete Vtg (VtgC) have been successfully isolated and purified as two different proteins with distinct molecular weights and antigenicity in various fish species, including tilapia (O. aureus [85] and O. mossambicus [86]), medaka [87], Japanese goby Acanthogobius flavimanus [88] and Sakhalin taimen [89]. In addition, three distinct types of Vtg have been purified or detected in mosquitofish Gambusia affinis [90], red seabream Pagrus major [91] and grey mullet [92].…”

Hepatic estrogen-responsive genes relating to oogenesis in cutthroat trout (Oncorhynchus clarki): The transcriptional induction in primary cultured hepatocytes and the in vitro promoter transactivation in responses to estradiol-17β

“…treatment in vivo in male and immature cutthroat trout , as were mRNA/protein levels in the liver of other salmonids (Amano et al, 2010;Boyce-Derricott et al, 2009;Hiramatsu et al, 1997;Thomas-Jones et al, 2003;Westerlund et al, 2001).…”