Differential Expression of Multiple Connexins in Rat Corpus and Cauda Epididymis at Various Postnatal Stages

Abstract

Direct cell-cell communication via the transfer of small molecules between neighboring cells in tissue is accomplished by gap junctions composed of various connexins (Cxs). Proper postnatal development of the epididymis is important for acquisition of male reproduction. The epididymal epithelium is composed of several cell types, and some of these cells are connected by gap junctions. The present study was conducted to determine the presence of Cx transcripts in the corpus and cauda epididymis. In addition, transcriptional changes of Cxs expressed during different postnatal stages were examined by real-time PCR analysis. In both epididymal regions, the same nine Cx transcripts of thirteen Cxs tested were detected. In the corpus epididymis, the highest levels of Cxs31.1 and 37 transcripts were observed at 45 days of age, and amounts of Cxs26, 30.3, and 32 transcripts increased with age and subsequently decreased in the elderly. Expression of Cx31 was greatly increased in the adult and elder stages, while Cxs40, 43, and 45 were abundant in the early postnatal stages. In the cauda epididymis, expression of Cxs26, 30.3, 31.1, 37, and 40 reached the highest levels at 5 months of age. The levels of Cxs31 and 32 mRNAs fluctuated throughout the postnatal period. The amounts of Cxs43 and 45 transcripts were more abundant during the late neonatal and prepubertal ages than later ages. These findings suggest that regional specification of the epididymis is partly regulated by differential expression of Cx genes during the postnatal developmental period.

Changes in Expression of Connexin Isoforms in the Caudal Epididymis of Adult Sprague-Dawley Rats exposed to Estradiol Benzoate or Flutamide at the Neonatal Age

“…Especially, this research shows expressional change of Cx 43 in the caudal epididymis, but not in the corpus epididymis (Lydka et al, 2011). As seen in our previous (Lee, 2013 & 2015) and present researches, Cx 43 is the most predominant form of Cx isoforms in the epididymis. Thus, it is important to notice the opposite effects of high-dose EB and low-dose flutamide treatments on expression of Cx 43 in the corpus and caudal epididymis.…”

“…The presence and expression of tissue-specific Cx isoforms have been determined by several researches (Goodengough et al, 1996; Willecke et al, 2002). The differential expression of Cx isoforms in the epididymis during postnatal period has been demonstrated by our previous and other researches (Dufresne et al, 2003; Han & Lee, 2013; Lee 2013; Pointis et al, 2005). Moreover, our recent findings have demonstrated that expression of Cx isoforms in the initial segment and corpus epididymis is differentially regulated by estradiol benzoate, an agonist of estradiol, or flutamide, a synthetic antiandrogen, which is administrated at the early neonatal and/or weaning age (Lee, 2014; Lee & Lee, 2015).…”

Effects of Exposure to Estradiol Benzoate or Flutamide at the Weaning Age on Expression of Connexins in the Caudal Epididymis of Adult Rat

“…Expression of several Cx isoforms has been found in many types of mammalian tissues and even a specific cell type (Goodenough & Paul, 2009). In case of the epididymis, the presence and expression of 8 to 9 different Cx isoforms have been identified from our earlier researches and others (Cry, 2011; Lee, 2013; Seo et al, 2010). Also, the expression of Cx isoforms in the epididymis is segmental specific and/or postnatal development age-specific (Lee, 2013; Seo et al, 2010).…”

“…In case of the epididymis, the presence and expression of 8 to 9 different Cx isoforms have been identified from our earlier researches and others (Cry, 2011; Lee, 2013; Seo et al, 2010). Also, the expression of Cx isoforms in the epididymis is segmental specific and/or postnatal development age-specific (Lee, 2013; Seo et al, 2010). Even though Cry et al (1996) has demonstrated the presence of Cx 43 in the base of the epithelium between basal and principal cells in the rat epididymis, little information is available for the localization of other Cx isoforms in the epididymis.…”

Expressional Modulation of Connexin Isoforms in the Initial Segment of Male Rat treated with Estradiol Benzoate or Flutamide

“…More than 20 Cx isoforms in mammals have been identified up to date (Meşe et al, 2007). Several researches have demonstrated the presence of Cxs in the male reproductive tract (Cry, 2011;Lee, 2013;Seo et al, 2010). Segment-specific expression of Cxs in the epididymis during postnatal development has been reported .…”