A novel intron variant in the prolactin gene associated with eggshell weight and thickness with putative alternative splicing patterns in chickens.

Raising Iraqi indigenous chickens (IIC) is restricted by their thin and low eggshell weights. Due to the importance of the prolactin (Prl) gene in regulating a wide range of egg production traits, this study assessed the potential genetic polymorphisms associated with Prl that may influence these traits. The polymorphism was examined in three Prl loci of the IIC breed (n = 120) in comparison with the standard Hyline breed (n = 120). The polymorphism of both breeds was associated with eggshell weight and thickness indices for 16 weeks, starting from the 44th to the 59th week. After genotyping three loci within Prl by polymerase chain reaction-single-stranded conformation polymorphism (SSCP) method, only one novel SNP was identified in intron 4, namely 129G>A. The identified intron SNP exerted a significant association with both eggshell thickness and weight indices throughout the investigation period. Birds with GG genotype exhibited higher indices of eggshell thickness and weight than those with the GA and AA genotypes, respectively. The employed in silico tools predicted a remarkable ability for the identified SNP to alter the mRNA splicing pattern, which might be related to altered prolactin activity in birds having an alternative allele A. This study is the first to suggest the significance of this novel intron SNP in assessing eggshell traits in chickens.

Retinal prolactin isoform PRLΔE1 sustains rod disease in inherited retinal degenerations.

PRLΔE1, a retina-specific isoform of prolactin, is expressed in multiple and diverse forms of canine inherited retinal degeneration (IRD). We find that while PRLΔE1 expression in rods is not associated with the initial phase of disease characterized by acute photoreceptor cell death, it is associated with the protracted phase of slow cell loss. Restoration of photoreceptors to a healthy state by gene-specific replacement therapy of individual IRDs successfully suppresses PRLΔE1 expression. Moreover, short-term PRLΔE1 silencing using shRNA results in preservation of outer nuclear layer thickness, suggesting PRLΔE1 drives retinal disease. However, longer-term observations reveal off-target toxic effects of the PRLΔE1 shRNA, precluding determination of its full therapeutic potential. Future research efforts aimed at enhancing the safety and specificity of PRLΔE1-targeting strategies may identify a potential universal intervention strategy for sustaining photoreceptors during the prolonged phase of multiple IRDs.

Association of polymorphic variants of prolactin (PRL) and beta-lactoglobulin (BLG) genes with resistance/susceptibility to mastitis in holstein cows.

The work aims to analyze the associations of polymorphic variants of the PRL and BLG genes with resistance and susceptibility to mastitis in Holstein cows. The experimental study consisted of the selection of biomaterial samples from 250 heads of Holstein cows aged 3 years divided into two groups (healthy and with a confirmed diagnosis of mastitis). The determination of animal genotypes was carried out using polymerase chain reaction and restriction fragment length polymorphism. The study of the nature of the association of polymorphic variants of the PRL and BLG gene with resistance/increased risk of mastitis established a significant deviation from the theoretically expected distribution of bBLG-HaeIII genotypes in the group of animals suffering from mastitis (the value of χ2 was 0.24). The bBLG-HaeIIIBB genotype can act as a marker of an increased risk of developing mastitis in Holstein cows; its frequency in the group of sick animals exceeds the frequency in the control group by more than 2 times (44.0 compared to 17.0%, respectively). The bBLG-HaeIIIAB genotype is significantly associated with mastitis resistance in Holstein cows; its frequency is 2 times lower than in the control group (28.0 compared to 54.0%).

Epigenetic control of adaptive or homeostatic splicing during interval-training activities.

Interval-training activities induce adaptive cellular changes without altering their fundamental identity, but the precise underlying molecular mechanisms are not fully understood. In this study, we demonstrate that interval-training depolarization (ITD) of pituitary cells triggers distinct adaptive or homeostatic splicing responses of alternative exons. This occurs while preserving the steady-state expression of the Prolactin and other hormone genes. The nature of these splicing responses depends on the exon's DNA methylation status, the methyl-C-binding protein MeCP2 and its associated CA-rich motif-binding hnRNP L. Interestingly, the steady expression of the Prolactin gene is also reliant on MeCP2, whose disruption leads to exacerbated multi-exon aberrant splicing and overexpression of the hormone gene transcripts upon ITD, similar to the observed hyperprolactinemia or activity-dependent aberrant splicing in Rett Syndrome. Therefore, epigenetic control is crucial for both adaptive and homeostatic splicing and particularly the steady expression of the Prolactin hormone gene during ITD. Disruption in this regulation may have significant implications for the development of progressive diseases.

The prolactin receptor: A cross-species comparison of gene structure, transcriptional regulation, tissue-specificity, and genetic variation.

The conserved and multifaceted functions of prolactin (PRL) are coordinated through varied distribution and expression of its cell-surface receptor (PRLR) across a range of tissues and physiological states. The resultant heterogeneous expression of PRLR mRNA and protein across different organs and cell types supports a wide range of PRL-regulated processes including reproduction, lactation, development, and homeostasis. Genetic variation within the PRLR gene also accounts for several phenotypes impacting agricultural production and human pathology. The goal of this review is to highlight the many elements that control differential expression of the PRLR across tissues, and the various phenotypes that exist across species due to variation in the PRLR gene.

Transcriptome analysis of pigeon pituitary gland: expression changes of genes encoding protein and peptide hormones at different breeding stages.

Unlike other poultry, parent pigeons produce "pigeon milk" in their crops to nurture their squabs, which is mainly controlled by prolactin (PRL). Exception for PRL, the pituitary gland may also release various other peptide and protein hormones. However, whether these hormones change during pigeon crop lactation and their potential physiological functions remain unclear. Here, to identify potential peptide or protein hormone genes that regulate crop lactation, we conducted transcriptome analysis of pigeon pituitary glands at 3 different breeding stages (the ceased stage-nonincubation and non-nurturing stage, the 11th d of the incubation, and the 1st d of the nurturing stage) using RNA sequencing (RNA-Seq). Our analysis identified a total of 15,191 mRNAs and screened out 297 differentially expressed genes (DEG), including PRL, VIP, etc. The expression abundance of PRL mRNA on the 1st d of the nurturing stage was respectively 4.93 and 3.62 folds higher when compared to the ceased stage and the 11th d of the incubation stage. Additionally, the expression abundance of VIP is higher in the 1st d of the nurturing stage than in the ceased stage. Protein-protein interaction (PPI) network and Molecular Complex Detection (MCODE) analysis identified several vital DEGs (e.g., GHRHR, VIP, etc.), being closely linked with hormone and enriched in neuropeptide signaling pathway and response to the hormone. Expression pattern analysis revealed that these DEGs exhibited 4 distinct expression patterns (profile 10, 16, 18, 19). Genes in profile 10 and 19 presented a trend with the highest expression level on 1st d of the nurturing stage, and functional enrichment analysis indicated that these genes are involved in neuropeptide hormone activity, receptor-ligand activity, and the extracellular matrix, etc. Taken together, being consistent with PRL, some genes encoding peptide and protein hormones (e.g., VIP) presented differentially expressed in different breeding stages. It suggests that these hormones may be involved in regulation of the crop lactation process or corresponding behavior in domestic pigeons. The results of this study help to gain new insights into the role of pituitary gland in regulating pigeon lactation.

PRL-mediated STAT5B/ARRB2 pathway promotes the progression of prostate cancer through the activation of MAPK signaling.

Previous study showed that higher expression of prolactin (PRL) was found in CRPC samples compared with hormone-naive prostate cancer (HNPC) and benign prostatic hyperplasia (BPH) samples. We further investigate the function of PRL in prostate cancer (PCa) and explored its downstream effects. We found heterogeneous expression of the PRLR in clinical prostate samples. The VCaP and 22Rv1 cells exhibited PRLR expression. Among the downstream proteins, STAT5B was the dominant subtype in clinical samples and cell lines. Human recombinant PRL stimulation of PCa cells with PRLR expression resulted in increased phosphorylation of STAT5B(pSTAT5B) and progression of PCa in vitro and in vivo, and STAT5B knockdown can suppress the malignant behavior of PCa. To understand the mechanism further, we performed Bioinformatic analysis, ChIP qPCR, and luciferase reporter gene assay. The results revealed that ARRB2 was the transcription target gene of STAT5B, and higher expression of ARRB2 was related to higher aggression and poorer prognosis of PCa. Additionally, Gene set enrichment analysis indicated that higher expression of ARRB2 was significantly enriched in the MAPK signaling pathway. Immunohistochemistry (IHC) demonstrated elevated pSTAT5B, ARRB2, and pERK1/2 expression levels in CRPC tissues compared to HNPC and BPH. Mechanically, ARRB2 enhanced the activation of the MAPK pathway by binding to ERK1/2, thereby promoting the phosphorylation of ERK1/2 (pERK1/2). In conclusion, our study demonstrated that PRL stimulation can promote the progression of PCa through STAT5B/ARRB2 pathway and activation of MAPK signaling, which can be suppressed by intervention targeting STAT5B. Blockade of the STAT5B can be a potential therapeutic target for PCa.

The prolactin receptor gene (PRLR) is linked and associated with the risk of polycystic ovarian syndrome.

The prolactin receptor gene (PRLR) may contribute to polycystic ovarian syndrome (PCOS) since it plays important roles in physiological ovarian functions. PRLR-knockout mice have irregular cycles and subfertility and variants in or around the PRLR gene were associated in humans with female testosterone levels and recurrent miscarriage. We tested 40 variants in the PRLR gene in 212 Italian families phenotyped by type 2 diabetes (T2D) and PCOS and found two intronic PRLR-variants (rs13436213 and rs1604428) significantly linked to and/or associated with the risk of PCOS. This is the first study to report PRLR as a novel risk gene in PCOS. Functional studies are needed to confirm these results.

Population Pharmacokinetic Analysis of Follicle-Stimulating Hormone During Ovarian Stimulation: Relation with Weight, Prolactin and Gene Polymorphism in THADA and ADIPOQ.

BACKGROUND: Personalisation strategies of ovarian stimulation for in vitro fertilisation (IVF)/ intracytoplasmic sperm injection (ICSI) treatments using exogenous follicle-stimulating hormone (FSH) have been extensively studied over the past 20 years. This research aimed to develop a FSH population pharmacokinetic (PPK) model taking into account the contribution of gene polymorphisms in Chinese reproductive-age women. METHODS: Data from 173 patients undergoing GnRH agonist down-regulation long protocols of IVF/ICSI treatment were collected. PPK analysis was subsequently conducted using the nonlinear mixed-effect model (NONMEM) software. Several covariates, including 18 single nucleotide polymorphisms, demographic factors and biological characteristics, were evaluated. The final PPK model was extensively validated using bootstrapping and normalised prediction error distribution, as well as external validation on an independent group of 35 patients. RESULTS: FSH PPK was accurately described by a one-compartment model with first-order absorption. The typical population value of apparent clearance was estimated to be 0.81 L/h [relative standard errors (RSE) 5.3%] with an inter-individual variability (IIV) of 16.0%. The typical apparent distribution volume was 8.36 L (RSE 9.7%, 59.7% IIV), and the absorption rate constant was estimated to be 0.0444 h-1 (RSE 9.1%). Body weight, basal prolactin concentration and the gene ADIPOQ (rs1501299) showed a significant covariate effect on the FSH clearance rate and exposure concentration. Genotypes of THADA (rs12478601) significantly influenced the distribution volume. Simulation results indicated that patients with the TT genotype of THADA (rs12478601) required a longer time to reach steady state and had less fluctuation in FSH levels. Model evaluations showed that the final model accurately and precisely described the observed data and demonstrated effective prediction performance. CONCLUSION: PPK models of FSH have been developed, which could potentially be used for FSH dosage individualisation in the clinical setting. CLINICAL TRIAL REGISTRATION: This study has been registered with the Chinese Clinical Trials Registry (ChiCTR2100049142).

Allele mining in prolactin receptor gene and its association with some economic traits in Egyptian goat breeds.

The objectives of the current study were to identify polymorphism in the prolactin receptor (PRLR) gene among three Egyptian goat breeds (Zaraibi, Damascus, and Barki) and to investigate the association between PRLR genotype, parity, season of kidding, and litter size factors with milk yield and reproductive traits of Zaraibi goats. One hundred and ninety blood samples were collected for DNA extraction, with 110 from Zaraibi, 40 from Barki, and 40 from Damascus breeds. Three genotypes, CC, CT and TT, for the prolactin receptor gene were identified in the 190 DNA samples using restriction fragment length polymorphism and were confirmed by direct sequencing technique. Milk yield during suckling and lactation periods in addition to age at first conception, gestation length, and litter size were determined in 110 Zaraibi goats. The Zaraibi goats recorded the highest heterozygosity (0.495) and the effective number of alleles (1.972). The g.62130C > T SNP showed a significant association (p < 0.01) with suckling, lactation, and total milk yield of Zaraibi goats with the highest values recorded at the third parity. Age at the first conception and gestation length traits were significantly influenced by the kidding season (p < 0.05) with younger age in autumn and shorter length in spring seasons. Milk yield during the suckling period was significantly (p < 0.01) higher in the case of triplets' litter size. The current study showed that litter size and parity played an important role in the amount of Zaraibi goats' milk yield. The g.62130C > T SNP of the PRLR gene may be a useful marker for assisted selection programs to improve goat milk yield during suckling and lactation periods with the heterozygous genotype CT recording the highest values.

Novel implication of the prolactin (PRL) gene in the comorbidity of type 2 diabetes and depression.

OBJECTIVE: The prolactin (PRL) system plays important behavioral, social, and metabolic roles, such as mediating social bonding and insulin secretion. Inherited dysfunction of the PRL pathway-related genes is associated with psychopathology and insulin resistance. We have previously suggested that the PRL system might be implicated in the comorbidity of psychiatric (depression) and type 2 diabetes (T2D) owing to the pleiotropy of PRL pathway-related genes. To our knowledge, no PRL variants have so far been reported in patients with either major depressive disorder (MDD) and/or T2D. PATIENTS AND METHODS: In this study, we analyzed 6 variants within the PRL gene and tested them for the presence of parametric linkage and/or linkage disequilibrium (LD, i.e., linkage and association) with familial MDD, T2D, and their comorbidity. RESULTS: We found, for the first time, that the PRL gene and its novel risk variants are linked to and in LD (i.e., linkage and association) with familial MDD, T2D, and MDD-T2D comorbidity. CONCLUSIONS: PRL might play a key role in mental-metabolic comorbidity and can be considered a novel gene in MDD and T2D.

Analysis of sperm chromatin packaging and reproductive biomarker to evaluate the consequence of advanced male age.

In this study, the semen parameters, sperm chromatin integrity, antioxidant enzyme levels, and reproductive hormone levels of subfertile male subjects from Pakistan were assessed in relation to their age. Data on the demographic characteristics of the 750 study participants, including their general health, body mass index (BMI), and reproductive status, were collected from subfertile men from Pakistan. Semen and blood were collected to determine standard semen parameters, sperm chromatin dispersion (Halosperm-SCD), sperm chromatin integrity using toluidine blue (TB) staining, sperm chromatin maturity using chromomycin A3 (CMA3+) staining, and reproductive hormone (FSH, LH, prolactin and testosterone levels). The patients were divided into three groups according to their age: Group 1 included male subjects aged 30 years or less (n = 90), Group 2 included male subjects between the ages of 31 and 40 years (n = 330), and Group 3 included male subjects over 40 years of age (n = 330). Conventional semen parameters, reactive oxygen species (ROS), superoxide dismutase (SOD), guaiacol peroxidase (GPX), catalase (CAT), and lipid peroxidation (MDA) did not statistically (p > 0.05) differ with increasing male age or between different age groups. When compared to younger men (<30 years), sperm SCD (23.2 ± 0.88%) was significantly (p = 0.01) lower as compared to male patients aged >40 years (26.6 ± 0.6%). The concentration of LH, FSH, and testosterone levels were comparable between the groups (p > 0.05), while a significant (p = 0.04) increase in sperm chromatin immaturity CMA3+ (30 ± 0.71%) was observed in the old age group (>40 years) compared to the <30-year group (26.6 ± 1.03%). A positive association was observed between advanced male age and sperm chromatin dispersion (SCD) (r = 0.124, p = 0.001) and decondensation (CMA3+) (r = 0.1, p = 0.009). Despite potential limitations, this study has been carried out with extensive information on the potential risk of male age on sperm integrity. The present study demonstrated the impact of male age on male reproductive health, as these patients had a higher percentage of sperm chromatin damage (SCD) in their semen. Sperm DNA damage assessment will help in the evaluation and diagnosis of the underlying cause of poor fertility and can help clinicians in selecting the right treatment options. Male age is one of the factors that have an impact on the decline in male fertility. As a result, it is preferable for patients receiving assisted reproductive technology to be younger.

[Association of the Level of Serum Prolactin with Polymorphic Variants of the GRIN2A, GPM3, and GPM7 Genes in Patients with Schizophrenia Taking Conventional and Atypical Antipsychotics].

The dopamine, serotonin and glutamate systems are jointly involved in the pathogenesis and pharmacotherapy of schizophrenia. We formulated a hypothesis that polymorphic variants of the GRIN2A, GRM3, and GRM7 genes may be associated with the development of hyperprolactinemia in patients with schizophrenia taking conventional and atypical antipsychotics as basic treatment. 432 Caucasian patients diagnosed with schizophrenia were examined. DNA was isolated from peripheral blood leukocytes using the standard phenol-chloroform method. For pilot genotyping, 12 SNPs in the GRIN2A gene, 4 SNPs in the GRM3 gene, and 6 SNPs in the GRM7 gene were selected. Allelic variants of the studied polymorphisms were determined by real-time PCR. The level of prolactin was determined by enzyme immunoassay. Among persons taking conventional antipsychotics, there were statistically significant differences in the distribution of genotype and allele frequencies in groups of patients with normal and elevated prolactin levels for the GRIN2A rs9989388 and GRIN2A rs7192557 polymorphic variants, as well as differences in serum prolactin levels depending on the genotype of the GRM7 rs3749380 polymorphic variant. Among persons taking atypical antipsychotics, statistically significant differences were found in the frequencies of genotypes and alleles of the GRM3 rs6465084 polymorphic variant. An association of polymorphic variants of the GRIN2A, GRM3, and GRM7 genes with the development of hyperprolactinemia in patients with schizophrenia taking conventional and atypical antipsychotics has been established for the first time. The identified associations of polymorphic variants of the GRIN2A, GRM3 and GRM7 genes with the development of hyperprolactinemia in patients with schizophrenia taking conventional and atypical antipsychotics have been established for the first time. These associations not only confirm the close connection of the dopaminergic, serotonergic, and glutamatergic systems in the development of schizophrenia, but also demonstrate the potential of taking into account the genetic component during therapy.

Isoform-specific knockdown of long and intermediate prolactin receptors interferes with evolution of B-cell neoplasms.

Prolactin (PRL) is elevated in B-cell-mediated lymphoproliferative diseases and promotes B-cell survival. Whether PRL or PRL receptors drive the evolution of B-cell malignancies is unknown. We measure changes in B cells after knocking down the pro-proliferative, anti-apoptotic long isoform of the PRL receptor (LFPRLR) in vivo in systemic lupus erythematosus (SLE)- and B-cell lymphoma-prone mouse models, and the long plus intermediate isoforms (LF/IFPRLR) in human B-cell malignancies. To knockdown LF/IFPRLRs without suppressing expression of the counteractive short PRLR isoforms (SFPRLRs), we employ splice-modulating DNA oligomers. In SLE-prone mice, LFPRLR knockdown reduces numbers and proliferation of pathogenic B-cell subsets and lowers the risk of B-cell transformation by downregulating expression of activation-induced cytidine deaminase. LFPRLR knockdown in lymphoma-prone mice reduces B-cell numbers and their expression of BCL2 and TCL1. In overt human B-cell malignancies, LF/IFPRLR knockdown reduces B-cell viability and their MYC and BCL2 expression. Unlike normal B cells, human B-cell malignancies secrete autocrine PRL and often express no SFPRLRs. Neutralization of secreted PRL reduces the viability of B-cell malignancies. Knockdown of LF/IFPRLR reduces the growth of human B-cell malignancies in vitro and in vivo. Thus, LF/IFPRLR knockdown is a highly specific approach to block the evolution of B-cell neoplasms.

Clock 3111 T/C and Period3 VNTR gene polymorphisms and proteins, and melatonin levels in women with infertility.

PURPOSE: One of the causes of infertility is circadian rhythm disorders. This study aimed to investigate Clock 3111 T/C and Period3 VNTR (variable number tandem repeat) gene polymorphisms and these gene proteins, some biochemical parameters, and circadian rhythm hormones in infertile women. METHODS: Thirty-five infertile women and thirty-one healthy fertile women were included. Blood samples were taken in the mid-luteal phase. DNAs obtained from peripheral blood were analyzed using polymerase chain reaction-restriction fragment length polymorphism methods. Follicle-stimulating hormone, LH (luteinizing hormone), estradiol, prolactin, free triiodothyronine, fT4 (free thyroxine), thyroid-stimulating hormone, testosterone, cortisol, progesterone, prolactin, ferritin, vitamin B12, and folate levels in serum samples were determined by the electrochemiluminescence immunoassay method. Melatonin, Clock, and Period3 protein levels were determined with ELISA kits. RESULTS: There was a significant difference in the frequency of Period3 DD (Per34/4) genotype between the groups. The Clock protein level of the infertile group was higher than the fertile group. Clock protein levels of the fertile group were positively correlated with estradiol levels and negatively correlated with LH, prolactin, and fT4 levels. PER3 protein levels of the infertile group were negatively correlated with LH levels. Melatonin levels of the fertile group were positively correlated with progesterone levels and negatively correlated with cortisol levels. Melatonin levels of the infertile group were positively correlated with LH levels and negatively correlated with cortisol levels. CONCLUSION: Per34/4 genotype may be an independent risk factor in infertile women. Different correlation results found in fertile and infertile women can form the basis for future studies.

Single nucleotide polymorphisms within exon four of the prolactin gene and their effect on milk traits in cattle populations of Ethiopia.

Bovine prolactin (PRL) gene is essential for the initiation and maintenance of lactation and exerts multiple effects on mammary alveoli to promote the synthesis and secretion of major components of milk. The objectives of this study were to identify mutations in PRL gene and to evaluate the mutations as potential markers of milk performance traits in cattle populations of Ethiopia. For this purpose, genomic DNA from whole blood was extracted through salting out procedure from 87 animals of five cattle populations of Ethiopia. Accordingly, three single nucleotide polymorphisms (SNPs) were identified of which one SNP g.8323T > A showed missense mutation while the other two SNPs revealed silent mutations. FST values showed statistically significant genetic differentiation among the studied populations. Intermediate polymorphic information content was noted for most SNPs, which indicates the presence of sufficient genetic variation at this locus. Two SNPs showed heterozygote deficiency as a result of positive FIS values. Only g.8398A > G SNP have statistically significant (p < 0.05) effect on average daily milk yield, fat and solid not fat percentage in all studied cattle populations. Therefore, g.8398A > G SNP identified in this study influences cattle milk production and may be used as possible candidate SNP for marker-assisted selection programs in cattle populations of Ethiopia.

Association of birth type and LHX4 gene polymorphism with reproductive hormones, growth hormone, and prolactin in Awassi ewes.

BACKGROUND: LIM homeobox transcription factor 4 (LHX4) is a promising candidate gene for mammalian reproductive traits. LHX4 polymorphism has previously been associated with phenotypic traits in goats and cattle. However, there have been no LHX4 gene polymorphisms identified in Awassi sheep. Therefore, this study investigated the effects of the LHX4 polymorphism on reproductive hormones, growth hormones, and prolactin in Awassi ewes. METHODS AND RESULTS: A total of 232 ewes between the ages of 3 and 4 years were selected for this study (123 single-progeny ewes and 109 twin-producing ewes). Serum was collected to measure reproductive hormones, growth hormone, and prolactin using ELISA kits made by ELK Biotechnology. Genomic DNA was extracted from sheep blood, genotyped, and sequenced to confirm variations in LHX4 (exon 1, 207 bp). Genotyping revealed three genotypes in 207 bp: AA, AG, and GG. Sequence analysis detected a novel mutation in exon 1: 160 A > G. Statistically, the 160 A > G SNP was significantly associated with the phenotypic traits. Ewes carrying AA genotypes had higher estrogen, progesterone, follicle-stimulating hormones/luteinizing hormones, and growth hormone, and lower prolactin levels (65.63 ± 3.84) (pg/mL), (6.67 ± 0.38) (ng/mL), (22.34 ± 1.27) (ng/mL)/(23.89 ± 2.13) (ng/mL), (1.30 ± 0.05) (ng/mL), and (13.16 ± 0.75) (pg/mL), respectively, compared to AG and GG genotypes in the fourth month of twin-pregnant ewes compared to single-pregnant ewes. CONCLUSION: This study suggests that the 160 A > G SNP negatively affects the Awassi sheep's hormone levels. It provides valuable insight into the sheep LHX4 gene, which could be an effective marker in marker-assisted selection.

Prolactin and the evolution of male pregnancy.

Prolactin (PRL) is a multifunctional hormone of broad physiological importance, and is involved in many aspects of fish reproduction, including the regulation of live birth (viviparity) and both male and female parental care. Previous research suggests that PRL also plays an important reproductive role in syngnathid fishes (seahorses, pipefish and seadragons), a group with a highly derived reproductive strategy, male pregnancy - how the PRL axis has come to be co-opted for male pregnancy remains unclear. We investigated the molecular evolution and expression of the genes for prolactin and its receptor (PRLR) in an evolutionarily diverse sampling of syngnathid fishes to explore how the co-option of PRL for male pregnancy has impacted its evolution, and to clarify whether the PRL axis is also involved in regulating reproductive function in species with more rudimentary forms of male pregnancy. In contrast to the majority of teleost fishes, all syngnathid fishes tested carry single copies of PRL and PRLR that cluster genetically within the PRL1 and PRLRa lineages of teleosts, respectively. PRL1 gene expression in seahorses and pipefish is restricted to the pituitary, while PRLRa is expressed in all tissues, including the brood pouch of species with both rudimentary and complex brooding structures. Pituitary PRL1 expression remains stable throughout pregnancy, but PRLRa expression is specifically upregulated in the male brood pouch during pregnancy, consistent with the higher affinity of pouch tissues for PRL hormone during embryonic incubation. Finally, immunohistochemistry of brood pouch tissues reveals that both PRL1 protein and PRLRa and Na+/K+ ATPase-positive cells line the inner pouch epithelium, suggesting that pituitary-derived PRL1 may be involved in brood pouch osmoregulation during pregnancy. Our data provide a unique molecular perspective on the evolution and expression of prolactin and its receptor during male pregnancy, and provide the foundation for further manipulative experiments exploring the role of PRL in this unique form of reproduction.

PRL-R Variants Are Not Only Associated With Prolactinomas But Also With Dopamine Agonist Resistance.

CONTEXT: Knockout prolactin receptor gene (PRL-R) mice are animal models for prolactinomas and PRL acts via autocrine/paracrine inhibiting lactotroph proliferation. Recently, variants of the PRL-R were identified in prolactinoma patients and their frequency was higher compared to individuals from the genomic database. OBJECTIVE: We analyzed PRL-R variants frequency in an extensive cohort of prolactinoma patients and evaluated their association with clinical, laboratorial, and imaging characteristics and hormonal response to cabergoline. DESIGN: Observational, retrospective, and cross-sectional study. SETTING: This study took place at the Neuroendocrinology Unit of Clinics Hospital, Medical School of University of São Paulo, Brazil, a tertiary referral center. PATIENTS AND METHODS: Study participants included adults with sporadic prolactinomas treated with cabergoline, where response to therapy was defined by prolactin normalization with up to 3 mg/week doses. DNA was extracted from blood samples and the PRL-R was analyzed by polymerase chain reaction techniques and automatic sequencing. The association of PRL-R variants with serum prolactin levels, maximal tumor diameter, tumor parasellar invasiveness, and response to cabergoline was analyzed. RESULTS: We found 6 PRL-R variants: p.Ile100(76)Val, p.Ile170(146)Leu, p.Glu400(376)Gln/p.Asn516(492)Ile, p.Glu470Asp e p.Ala591Pro; the last 2 are newly described in prolactinomas' patients. The variants p.Glu400(376)Gln/p.Asn516(492)Ile and p.Ala591Pro were more frequent amongst patients compared to genomic databases, and the p.Asn516(492)Ile showed pathogenic potential using in silico analysis as previously described. PRL-R variants were associated with male sex (P = 0.015), higher serum PRL levels (P = 0.007), larger tumors (P = 0.001), and cabergoline resistance (P < 0.001). CONCLUSIONS: The prolactin/prolactin receptor system seems to be related to prolactinoma tumorigenesis and cabergoline resistance. Additional studies are needed to better understand the PRL-R variants' role and their potential as therapeutic targets.

Association analysis of prolactin and prolactin receptor genes with selected productive and reproductive traits in Egyptian buffalo.

A total of 266 records of buffalo raised in two experimental herds in Egypt were assessed to detect prolactin (PRL) and prolactin receptor (PRLR) genes' polymorphism using PCR-Single Strand Conformational Polymorphism (SSCP) and PCR-Restricted Fragment Length Polymorphism (RFLP) techniques as well as to investigate their association with calf birth weight (BW), weaning weight (WW), lactation period (LP), total milk yield (TMY), stillbirth, calving ease (CE), gestation length (GL), postpartum interval to pregnancy (PPIP), calving interval (CI), and age at first calving (AFC). Predicted breeding values were estimated and used in the association with detected genotypes. A monomorphic pattern of the studied PRL 156 bp segment was recorded and absence of its polymorphism in buffalo was corroborated. We also determined polymorphism of PRLR reflected in three loci: PRLR2, PRLR4, and PRLR9. Significant differences among PRLP9 genotypes (AA, AB, and BB) were displayed for all studied traits as well as among PRLR2 genotypes, except for CE, while PRLR4 genotypes significantly differed only in BW, WW, TMY, stillbirth, GL, and AFC. In practice, strong associations among genotypes of the PRLR gene and the traits of interest candidate this gene to be selective in Egyptian buffalo breeding for improving both productive and reproductive traits.