Expression of Oestrogen Receptors <i>α</i> and <i>β</i> and of Aromatase in the Testis of Immature and Mature Boars

Mutembei, Henry; Pesch, S.; Schuler, Gerhard; Hoffmann, Bernd

doi:10.1111/j.1439-0531.2005.00586.x

Cited by 70 publications

(65 citation statements)

References 59 publications

(65 reference statements)

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“…A change of aromatase expression was demonstrated in early postnatal rats, where aromatase is expressed in Sertoli cells but its expression shifts to Leydig cells in mature rats (Tsai-Morris et al 1985). The pig is unique due to its high amounts of estrogens (Claus et al 1985), which are exclusively synthesized in Leydig cells of mature boars (Mutembei et al 2005). The present study presents first data on aromatase localization by immunocytochemistry in fetal pigs.…”

Section: Discussionmentioning

confidence: 85%

Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

Haeussler

Wagner²,

Welter³

et al. 2007

Reproduction

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Male pig fetuses secrete considerable amounts of estrogens, but the location of aromatase activity within the fetal testis is not known. The location of aromatase expression was investigated by immunocytochemistry in fetal testes from week 6 (nZ5), weeks 10, 13, and 15 (each: nZ6) of gestation and additionally in neonates (nZ4). Blood was sampled from the umbilical artery of fetuses and jugular vein of neonates. Histological evaluation of testes involved morphological criteria and counting of Leydig cells, Sertoli cells, and gonocytes. Aromatase activity was localized immunocytochemically and quantified by the percentage of positive stained cells within the same cell type. Aromatase expression was further characterized by quantitative RT-PCR. Concentrations of estrogens, testosterone, FSH, and LH were measured in blood plasma. Total estrogens increased from week 10 to a maximum of 31.03 nmol/l in week 15. Increased testosterone concentrations were only measured at week 6 and were paralleled by slightly elevated estrogens. Thereafter, testosterone dropped and was low throughout. The increase of estrogens was not paralleled by a similar increase of FSH and LH but was related to the increase of the total number of Leydig cells. This increase was also found for mRNA expression. Both Leydig cells and gonocytes were identified as contributors to estrogen formation. Gonocytes were the main source of aromatase at week 10, when gene expression by Leydig cells is low due to the preparation of a wave of Leydig cell mitosis. Reproduction (2007) 133 323-330

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Section: Discussionmentioning

confidence: 85%

Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

Haeussler

Wagner²,

Welter³

et al. 2007

Reproduction

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“…ERs play an important role in activating signaling pathways leading to sperm capacitation, essential for further successful fertilization. ERs have been detected in the sperm of many species, for example, human (Aquila et al 2004, Solakidi et al 2005, boar (Mutembei et al 2005), rooster (Kwon et al 1995), rat (Pellettier et al 2000), but failed to be detected so far in mouse spermatozoa. In this study, the 64 kDa protein corresponding to ERB was detected to be present in sperm from cauda epididymis using immunoprotein detection.…”

Section: Discussionmentioning

confidence: 99%

The slower the better: how sperm capacitation and acrosome reaction is modified in the presence of estrogens

Šebková

Černá²,

Děd³

et al. 2012

Reproduction

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In order for mammalian sperm to obtain a fertilizing ability, they must undergo a complex of molecular changes, called capacitation. During capacitation, steroidal compounds can exert a fast nongenomic response in sperm through their interaction with plasma membrane receptors, and activate crucial signaling pathways leading to time-dependent protein tyrosine phosphorylation (TyrP). Estrogen receptor beta was detected in epididymal mouse sperm; therefore, the effect of 17B-estradiol, estrone, estriol, and 17A-ethynylestradiol on mouse sperm capacitation in vitro was investigated. The effect was evaluated by positive TyrP in sperm heads and in the whole sperm lysates. Simultaneously, the state of the acrosome after the calcium ionophore-induced acrosome reaction was assessed. Generally, estrogens displayed a time and concentration-dependent stimulatory effect on sperm TyrP during capacitation. In contrast, the number of sperm that underwent the acrosome reaction was lower in the experimental groups. It has been demonstrated that both natural and synthetic estrogens can modify the physiological progress of mouse sperm capacitation. The potential risk in the procapacitation effect of estrogens can also be seen in the decreased ability of sperm to undergo the acrosome reaction. In conclusion, the capacitating ability of sperm can be significantly lowered by increasing the level of estrogens in the environment.

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“…Examination of multiple regression relations showed that the levels of testicular hormones testosterone, estrone sulphate and free estrone in combination with testes and bulbo-urethral gland sizes were the best predictors of skatole in fat (Zamaratskaia et al, 2005d). The boar is known for its high amounts of estrogens (Claus and Hoffmann, 1980), which are produced in testicular Leydig cells (Raeside and Renaud, 1983;Mutembei et al, 2005) and are positively correlated to skatole levels Zamaratskaia et al, 2005c).…”

Section: Androstenone Skatole and Hormonal Status Of Animalsmentioning

confidence: 99%

Biochemical, nutritional and genetic effects on boar taint in entire male pigs

Zamaratskaia

Squires

2009

Animal

191

179

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Pork odour is to a great extent affected by the presence of malodorous compounds, mainly androstenone and skatole. The present review outlines the current state of knowledge about factors involved in the regulation of androstenone and skatole in entire male pigs. Androstenone is a pheromonal steroid synthesised in the testes and metabolised in the liver. Part of androstenone accumulates in adipose tissue causing a urine-like odour. Skatole is produced in the large intestine by bacterial degradation of tryptophan and metabolised by hepatic cytochrome P450 enzymes and sulphotransferase. The un-metabolised part accumulates in adipose tissue, causing faecal-like odour. Androstenone levels are mostly determined by genetic factors and stage of puberty, whereas skatole levels in addition to genetic background and hormonal status of the pigs are also controlled by nutritional and environmental factors. To reduce the risk of tainted carcasses entering the market, male pigs are surgically castrated in many countries. However, entire males compared to castrates have superior production characteristics: higher growth rate, better feed efficiency and leaner carcasses. Additionally, animal welfare aspects are currently of particular importance in light of increasing consumers' concerns. Nutrition, hormonal status, genetic influence on boar taint compounds and the methods to develop genetic markers are discussed. Boar taint due to high levels of skatole and androstenone is moderately heritable and not all market weight entire males have boar taint; it should thus be possible to select for pigs that do not have boar taint. In these studies, it is critical to assess the steroidogenic potential of the pigs in order to separate late-maturing pigs from those with a low genetic potential for boar taint. A number of candidate genes for boar taint have been identified and work is continuing to develop genetic markers for low boar taint. More research is needed to clarify the factors involved in the development of boar taint and to develop additional methods to prevent the accumulation of high concentrations of skatole and androstenone in fat. This review proposes those areas requiring further research.

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Expression of Oestrogen Receptors α and β and of Aromatase in the Testis of Immature and Mature Boars

Cited by 70 publications

References 59 publications

Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

Changes of testicular aromatase expression during fetal development in male pigs (sus scrofa)

The slower the better: how sperm capacitation and acrosome reaction is modified in the presence of estrogens

Biochemical, nutritional and genetic effects on boar taint in entire male pigs

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