Development and application of a reverse-transcription recombinase-aided amplification assay for subgroup J Avian leukosis virus.

Subgroup J Avian leukosis virus (ALV-J) is an important pathogen of poultry tumor diseases. Since its discovery, it has caused significant economic losses to the poultry industry. Thus, the rapid detection of molecular level with strong specificity is particularly important whether poultry are infected with ALV-J. In this study, we designed primers and probe for real-time fluorescent reverse-transcription recombinase-aided amplification assay (RT-RAA) based on the ALV-J gp85 sequence. We had established a real-time fluorescent RT-RAA method and confirmed this system by verifying the specificity and sensitivity of the primers and probe. In addition, repeatability tests and clinical sample regression tests were used for preliminary evaluation of this detection method. The sensitivity of established method was about 101 copies/µL, and the repeatability of the CV of the CT value is 4%, indicating repeatability is good. Moreover, there was no cross-reactivity with NDV, IBV, IBDV, H9N2, MDV, and REV, and other avian leukosis virus subgroups, such as subgroups A, B, C, D, K and E. Importantly, the real-time fluorescent RT-RAA completed the test within 30 min at a constant temperature of 41°C. Forty-two clinical samples with known background were tested, and the test results were coincided with 100%. Overall, these results suggested that the real-time fluorescent RT-RAA developed in this study had strong specificity, high sensitivity, and good feasibility. The method is simple, easy, and portable, that is suitable for clinical and laboratory diagnosis, and provides technical support for the prevention and control of ALV-J.

[Clinical application progress of bioresorbable vascular scaffolds in lower extremities arteriosclerotic obliterans].

Endovascular technology has become the first choice for the treatment of lower extremities arteriosclerotic obliterans. Bioresorbable vascular scaffolds have attracted more and more attention as a choice of endovascular technology. In the last decade, poly(L-lactic acid) bioresorbable scaffolds with or without drug coating have shown acceptable medium and long-term safety and efficacy in lower extremities arteriosclerotic obliterans, but the lesions of the subjects were relatively simple. Magnesium alloy bioresorbable scaffolds are safe but less effective in the treatment of lower extremities arteriosclerotic obliterans. Both iron and zinc alloy bioresorbable scaffolds have shown considerable results in animal experiments. In particular, the success of implantation of drug-coated iron alloy bioresorbable scaffolds in below-the-knee artery indicated that the iron alloy bioresorbable scaffolds have officially entered the clinical trial stage. Through the comprehensive summation of the previous clinical and experimental data of bioresorbable vascular scaffolds and the pathological characteristics of lower extremities arteriosclerotic obliterans, it is shown that the drug-coated poly(L-lactic acid) bioresorbable scaffolds and iron alloy bioresorbable scaffolds will have greater development potential in the treatment of lower extremities arteriosclerotic obliterans.

[Recurrent maxillary sinus pleomorphic gonadoma into myoepithelial carcinoma: a case report].

Summary A 44-year-old woman with left nasal obstruction and facial numbness for 4 months was admitted to hospital. The patient did not have amblyopia, vision loss, runny nose with blood, dizziness ,headache or other discomfort.In 1991 and 2001, the patient were pathologically diagnosed as pleomorphic adenomas.CT of nasal cavity and paranasal sinuses showed that in the left maxillary sinus there was an about 4.4 cm×4.5 cm×4.7 cm large mass soft tissue density, showing expansive growth protruding into the left orbital floor.MRI showed that the lumped short T1 signal was seen in the left maxillary sinus and the linear long T1 signal was seen in the left nasal cavity, and the liquid accumulation signal foci could be seen in the left maxillary sinus.Postoperative pathological findings: （left maxillary sinus mass） Combining morphology, immunohistochemical results and medical history, consistent with pleomorphic adenoma carcinogenesis （cancer in pleomorphic adenoma）, carcinogenesis type is myoepithelial carcinoma.

[Metastases of cervical cancer to the nasal cavity and paranasal sinus with maxillofacial symptoms: a case report].

A 41 year old female complained of left eyelid, cheek and face erythema, swelling with pain for 7 days. She was diagnosed with cervical squamous cell carcinoma, stage ⅢA a year ago. The anterior rhinoscopy examination showed that the dry scab adheres to the left nasal cavity, and a small amount of reddish mass were found, and the touch was brittle. A computed tomography (CT) scan of paranasal sinus revealed the soft tissue of left eyelid and buccal was slightly swollen, and dense shadow could be seen in left maxillary sinus and ethmoid sinus. Last, combined with the history of cervical cancer, histopathology and immunohistochemical results, cervical squamous cell carcinoma metastatic to the nasal cavity, sinuses and hard palate was considered.

[Clinical analysis of 42 cases of nasal natural killer/T-cell lymphoma prominently presenting as ocular symptoms].

Objective:To investigate the clinical features and prognosis of nasal natural killer/T-cell lymphoma(NKTL) with obvious ocular symptoms.Method:We retrospectively analyzed the clinical data of 42 patients with nasal NKTL who prominently showed eye symptoms and were treated from January 2011 to December 2017.Result:After treatment,the patients received complete remission(CR) in 19 cases and partial remission(PR) in 9 cases. The total effective rate was 66.67%.Median followup time was 39 months and 18 patients died.In this study, there was no correlation between sex and prognosis(P>0.05).Age＞60 years was not related to the prognosis of the patients(P>0.05).The 3-year survival rate of patients treated with radiotherapy and chemotherapy was higher than that of patients treated with radiotherapy or chemotherapy alone(73.3%, 16.7%，P<0.01). The 3-year survival rate of patients with B symptoms was 41.7%, which was not related to prognosis(P>0.05).The prognosis of EBV-DNA positive patients was poor(P<0.01). Twenty-six patients with stage Ⅰ and Ⅱ had a better prognosis(P<0.01). Patients with international prognostic index(IPI) ≤1 had a better prognosis than those with IPI≥2(83.3 %, 37.5%，P<0.01).Conclusion:Nasal NKTL lymphomas with prominent ocular symptoms are difficult to diagnose early and easy to be misdiagnosed. Clinicians should make a definite diagnosis by pathological biopsy and immunohistochemistry as soon as possible, and assist in diagnosis by EBER in situ hybridization if necessary.

L-butyl phthalein improves neural function of vascular dementia mice by regulating the PI3K/AKT signaling pathway.

OBJECTIVE: L-3-n-butylphthalide (L-NBP) is a type of anti-ischemic cranial nerve protective drug that may act on vascular dementia (VD). Phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT/PKB) signaling pathway can up-regulate B-cell lymphoma 2 (Bcl-2) expression, reduce reactive oxygen species (ROS) production, and alleviate cell apoptosis. This study aimed at investigating the role of L-NBP on neurological function and cell apoptosis in VD mouse through regulating PI3K/AKT signaling pathway. MATERIALS AND METHODS: The mice were divided into four groups, including Sham, VD, VD + solvent, and VD + L-NBP. HT22 cells were cultured in vitro and treated by ischemia/reperfusion (I/R). HT22 cells were divided into four groups, including I/R, VD + solvent, VD + L-NBP, and VD + L-NBP + LY294002 groups. Phosphorylated AKT (p-AKT) and Bcl-2 expressions were tested. ROS content in hippocampus tissue was detected by flow cytometry. Cell apoptosis was evaluated by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay. RESULTS: ROS content and cell apoptosis increased, while p-AKT and Bcl-2 expressions reduced in hippocampus tissue from VD group compared with sham group. L-NBP significantly up-regulated p-AKT and Bcl-2 expressions and decreased ROS content and cell apoptosis in hippocampus tissue. I/R treatment markedly induced HT22 cell apoptosis and ROS production, and reduced p-AKT and Bcl-2 expressions. L-NBP treatment markedly up-regulated p-AKT and Bcl-2 levels, restrained cell apoptosis, and reduced ROS content in TH22 cells intervened by I/R. LY294002 apparently attenuated the protective effect of L-NBP on HT22 cells. CONCLUSIONS: L-NBP protects VD by up-regulating PI3K/AKT signaling pathway, elevating Bcl-2 expression, reducing nerve cell apoptosis, and restraining ROS production.

[Drug coated balloon with paclitaxel for the treatment of symptomatic peripheral artery disease: early and midterm results].

OBJECTIVE: To evaluate the safety and efficacy of the drug coated balloon (DCB) with paclitaxel in patients with symptomatic peripheral artery disease (PAD). METHODS: The clinical data of 18 patients, who were diagnosed as PAD and treated with DCB from October 2013 to June 2014 in Department of Vascular Surgery, People's Liberation Army General Hospital, were retrospectively analyzed.Thirteen male and 5 female patients were in the series, the mean age of the patients was (65±7) years, and the Rutherford's categories were level 3 to 5. Patients were followed up at 3- and 6-month postoperative. The main efficacy end point were late lumen loss(LLL), rate of restenosis and clinically driven target lesion revascularization (TLR). Meanwhile, the clinical events were recorded. RESULTS: Mean lesion length, the percentage of total occlusions and the percentage of in-stent restenosis were (138±91) mm, 9/18 and 2/18, respectively. Rate of technical success was 18/18. At 6-month postoperative, LLL, rate of restenosis and TLR were (0.1±0.9) mm, 2/14 and 0, respectively. There was no deaths or no amputations. CONCLUSION: DCB with paclitaxel is safe in patients with PAD, and associated with reductions in LLL, restenosis and clinically driven TLR 6-month postoperative.

Molecular Identification and Characterization of Tomato zonate spot virus in Tobacco in Guangxi, China.

In Guangxi Province of southwest China, diseases caused by Tospoviruses (family Bunyaviridae) pose a serious threat to tobacco (Nicotiana tobacum) production. During surveys conducted annually at Xinrong Village in Jingxi County from 2008 to 2010, more than 130 ha of fields were found to have 10 to 50% of plants exhibiting symptoms similar to spotted wilt caused by Tomato spotted wilt virus (TSWV). During this period, disease symptoms at similar prevalence and incidence were also found at Fushan, Debao County in most of the cultivars produced in these areas, including Yunyan 85, 87, 92, 97, and K326. Symptoms on tobacco varied but commonly included dwarfing, midrib browning, distorted apical buds, and concentric ringspots that coalesced to form large areas of dead leaf tissue. Mechanical inoculation from diseased tobacco leaves with concentric ringspots back to tobacco cv. Yunyan 85 or 87, resulted in 12 of 16 plants with symptoms similar to those observed in the field. No symptoms on plants developed following inoculation with buffer only. Symptoms found in the field resembled those caused by TSWV. However, testing using TSWV-specific antiserum was shown to be negative by double-antibody sandwich-ELISA (Agdia, Elkhart, IN). Total RNA was extracted from 27 diseased tobacco plants collected from different regions in Guangxi using Trizol reagent (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions. RNA extracts were amplified by reverse transcription (RT)-PCR using the degenerate primers T2740 (ATGGGDATNTTTGATTTCATG) and T3920c (TCATGCTCATSAGRTAAATYTCTCT) designed to target the partial RNA-dependent RNA polymerase (RdRp) sequence of members in the genus Tospovirus (3). Amplification was performed at 42°C for 60 min, followed by 35 cycles of PCR (30 s denaturation at 94°C, 45 s annealing at 55°C, and 30 s extension at 72°C) and a 7-min final extension at 72°C. A PCR product of approximately 1.2 kb was amplified from 21 diseased plants. RT-PCR amplicons were cloned into the pUC19-T Simple Vector (TaKaRa, Dalian, China) and sequenced in both directions. Sequences were assembled and analyzed by DNAStar 5.01 (DNASTAR, Madison, WI). Sequences of representative isolates were deposited in GenBank (Accession Nos. JN020022 to JN020027). The 1.2-kb partial RdRp sequences of these isolates were shown to have 94.4 to 95.3% nucleotide identity and 96.5 to 97.5% amino acids identity to Tomato zonate spot virus (TZSV) (GenBank Accession No. NC_010491) (1). Among these TZSV isolates from Guangxi, the partial RdRp sequences have 98.0 to 99.4% nucleotide identity and 98.8 to 100% amino acids identity with each other. The presence of TZSV was further confirmed in diseased tobacco plants by indirect ELISA using antiserum of TZSV (provided by Prof. Zhongkai Zhang, Agricultural Academy of Yunnan, China). TZSV has been characterized as a novel tospovirus on various hosts including tobacco in Yunnan province (1,2). To our knowledge, this is the first report of TZSV-associated disease on tobacco in Guangxi Province, southwest China. Further work is necessary to study the epidemiology and management of the disease. References: (1) J. Dong et al. Arch. Virol. 153:855, 2008. (2) J. Dong et al. J. Insect Sci. 10:166, 2010. (3) Y. Lin. Master Thesis. National Chung Hsing University, Taichung, Taiwan, Republic of China, 2007.

Isolation and characterization of two novel forms of the human prolactin receptor generated by alternative splicing of a newly identified exon 11.

We have identified a novel exon 11 of the human prolactin receptor (hPRLR) gene that is distinct from its rodent counterparts and have demonstrated the presence of two novel short forms of the hPRLR (S1(a) and S1(b)), which are derived from alternative splicing of exons 10 and 11. S1(a) encodes 376 amino acids (aa) that contain partial exon 10 and a unique 39-aa C-terminal region encoded by exon 11. S1(b) encodes 288 aa that lack the entire exon 10 and contains 3 amino acids at the C terminus derived from exon 11 using a shifted reading frame. These short forms, which were found in several normal tissues and in breast cancer cell lines, were expressed as cell surface receptors and possessed binding affinities comparable with the long form. Unlike the long form, neither short form was able to mediate the activation of the beta-casein gene promoter induced by prolactin. Instead they acted as dominant negative forms when co-expressed with the long form in transfected cells. Due to a marked difference in the cellular levels between the two short forms in transfected cells, S1(b) was more effective in inhibiting the prolactin-induced activation of the beta-casein gene promoter mediated by the long form of the receptor. The low cellular level of S1(a) was due to its more rapid turnover than the S1(b) protein. This is attributable to specific residues within the C-terminal unique 39 amino acids of the S1(a) form and may represent a new mechanism by which the hPRLR is modulated at the post-translational level. Since both short forms contain abbreviated cytoplasmic domains with unique C termini, they may also exhibit distinct signaling pathways in addition to modulating the signaling from the long form of the receptor. These receptors may therefore play important roles in the diversified actions of prolactin in human tissues.

The human prolactin receptor gene structure and alternative promoter utilization: the generic promoter hPIII and a novel human promoter hP(N).

The 5'-untranslated region of the human prolactin receptor (hPRLR) gene contains two alternative first exons, hE1(3), the human counterpart of the rat and mouse E1(3) and a novel human type of alternative first exon termed hE1N, also a common non-coding exon 2 and a third exon containing the translation initiation codon. hE1(3) was localized approximately 800 bp 5' from the hE1N in the genome. The two distinct first exons hE1(3) and hE1N are expressed in human breast tissue, breast cancer cells, gonads and liver. Overall, the transcript containing hE1(3) is prevalent in most tissues. The coding region of the gene comprises eight exons (exon 3-10), in which exon 10 encodes most of the intracellular domain. hE1(3) and hE1N are transcribed from alternative promoters hPIII and hP(N), respectively. The hPIII, containing identical Sp1 and C/EBP elements as in the rodent promoters, shares 81% similarity in the region -480/-106 to both the rat and mouse. The novel promoter hP(N) contains putative binding sites for ETS-family proteins and a half-site for nuclear receptors. Therefore, both promoters likely utilize distinct mechanisms in controlling the hPRLR gene transcription. The different promoter utilization of the hPRLR gene in diverse tissues may confer differential prolactin response through activation of different promoters.

Effect of strategic feed supplementation on productive and reproductive performance in yak cows.

A total of 2230 yak cows (5-13 years of age) in two populations with different milking systems were investigated. One population had a system of milking once a day (MOD), and the other population twice a day (MTD). The average milk yield of MOD cows was 0.7 +/- 0.2 kg/day within a milking period of 109 +/- 9 days. This compared with an average of 1.24 +/- 0.3 kg/day in 127 +/- 6 days in MTD yaks (p < 0.01). The cows showed a calving rate of 71% under the MOD system and 51.4% under the MTD system. Three farms with a total of 104 MTD cows between six and 12 years of age were used to provide three different feeding groups. The groups were fed with, or without oat hay or highland barley straw in amounts of 1-1.5 kg/head/day from December to April. The three farms were designated as Farm I, Farm II, and Farm III. Farm I had 41 cows with body weight of 230 +/- 67 kg each for grazing with no supplement (GNS). Farm II had 30 animals with body weight of 216 +/- 28 kg each for grazing + oat hay (GOH). Farm III had 33 animals body weight of 221 +/- 34 kg each for grazing + highland barely straw (GBS). The calving rates of the cows in GOH and GBS were 23 and 19% higher, respectively, than GNS cows (p < 0.01), and the highest rate reached 76.7% in GOH. The live weight loss of the cows in GNS was considerably higher (p < 0.01) than in the two other groups. Ten GOH cows and 12 GNS cows were used to collect milk samples for measuring the progesterone concentration using RIA kits provided by IAEA/FAO: Milk was sampled every five days from calving until 90 days postpartum. In the unsupplemented group, milk progesterone (P4) levels suggested that cows had started cyclic ovarian activity by 40 days postpartum, whereas only 25% had been observed in estrus. In the supplemented group, 80% of cows had started cyclic ovarian activity by the same time and 70% had been seen in estrus. Two types of cyclic activity in terms of progesterone changed were found. With Type I (normal), 50 and 80% of cows from GNS and GOH, respectively, had cyclic changes of P4 in milk at 40 days postpartum. With Type II, the P4 levels in the milk remained 0.89 ng/ml until 90 days postpartum. A total of 46 grazing cows between five and 13 years of age (body weight 214 +/- 68 kg) was used to collect blood samples to measure concentrations of nutrient of metabolites at two weeks pre-calving and at two weeks, two months and four months postcalving, respectively. The concentrations of nutrient metabolites [albumin, globulin, urea, beta-hydroxybutyrate (BHB) and inorganic phosphorus] suggested general underfeeding of energy and protein in the winter/late pregnancy period with some recovery in lactation. Energy constraints appeared again as the summer progressed. No dietary phosphate deficiency was found. BHB and albumin testing on serum yaks could be a useful tool to identify poor nutritional status during the winter and so illustrate the need for supplementation.

Transcriptional regulation of the generic promoter III of the rat prolactin receptor gene by C/EBPbeta and Sp1.

Three promoters are operative in the rat prolactin receptor gene as follows: promoter I (PI) and II (PII) are specific for the gonads and liver, respectively, and promoter III (PIII) is common to several tissues. To investigate the mechanisms controlling the activity of promoter III, its regulatory elements and transcription factors were characterized in gonadal and non-gonadal cells. The TATA-less PIII domain was localized to the region -437 to -179 (ATG +1) containing the 5'-flanking region and part of the non-coding first exon. Within the promoter domain, a functional CAAT-box/enhancer binding protein (C/EBP) (-398) and an Sp1 element (-386), which bind C/EBPbeta and Sp1/Sp3, respectively, contribute individually to promoter activation in gonadal and non-gonadal cells. However, significant redundancy was demonstrated between these elements in non-gonadal cells. Additionally, an element within the non-coding exon 1 (-338) is also required for promoter activity. Activation of PIII by the widely expressed Sp1 and C/EBPbeta factors explains its common utilization in multiple tissues. Moreover, whereas the rat and mouse PIII share similar structure and function, the mouse PI lacks the functional SF-1 element and hence is inactive. These findings indicate that promoter III is of central importance in prolactin receptor gene transcription across species.

Prolactin receptor gene diversity: structure and regulation.

The diverse functionality of prolactin and the wide expression of the prolactin receptor suggest a complex system regulated by this polypeptide hormone. Different hormone and receptor forms, as well as differential signal transduction pathways, contribute to the functional diversity of prolactin's actions. The heterogeneity of rat prolactin receptor gene transcripts in their 5'-untranslated region has led to the recognition of multiple and tissue-specific utilization of prolactin receptor gene promoters in gonadal and non-gonadal tissues. These findings have provided insights into the molecular bases for the diversity of prolactin's actions. It is now clear that cellular responsiveness to prolactin can be regulated through differential promoter control of the expression of the surface receptors for prolactin in different target tissues.

Induction of chinook salmon growth hormone promoter activity by the adenosine 3',5'-monophosphate (cAMP)-dependent pathway involves two cAMP-response elements with the CGTCA motif and the pituitary-specific transcription factor Pit-1.

In this study, the functional role of two cAMP-response elements (CRE) in the promoter of the chinook salmon GH gene and their interactions with the transcription factor Pit-1 in regulating GH gene expression were examined. A chimeric construct of the chloramphenicol acetyltransferase (CAT) reporter gene with the CRE-containing GH promoter (pGH.CAT) was transiently transfected into primary cultures of rainbow trout pituitary cells. The expression of CAT activity was stimulated by an adenylate cyclase activator forskolin as well as a membrane-permeant cAMP analog 8-bromo-cAMP. Furthermore, these stimulatory responses were inhibited by a protein kinase A inhibitor H89, suggesting that these CREs are functionally coupled to the adenylate cyclase-cAMP-protein kinase A cascade. This hypothesis is supported by parallel studies using GH4ZR7 cells, a rat pituitary cell line stably transfected with dopamine D2 receptors. In this cell line, D2 receptor activation is known to inhibit adenylate cyclase activity and cAMP synthesis. Stimulation with a nonselective dopamine agonist, apomorphine, or a D2-specific agonist, Ly171555, suppressed the expression of pGH.CAT in GH4ZR7 cells, and this inhibition was blocked by simultaneous treatment with forskolin. These results indicate that inhibition of the cAMP-dependent pathway reduces the basal promoter activity of the CRE-containing pGH.CAT. The functionality of these CREs was further confirmed by deletion analysis and site-specific mutagenesis. In trout pituitary cells, the cAMP inducibility of pGH.CAT was inhibited after deleting the CRE-containing sequence from the GH promoter. When the CRE-containing sequence was cloned into a CAT construct with a viral thymidine kinase promoter, a significant elevation of cAMP inducibility was observed. This stimulatory response, however, was abolished by mutating the core sequence, CGTCA, in these CREs, suggesting that these cis-acting elements confer cAMP inducibility to the salmon GH gene. The interactions between CREs and the transcription factor Pit-1 in mediating GH gene expression were also examined. In HeLa cells, a human cervical cancer cell line deficient in Pit-1, both basal and cAMP-induced expression of pGH.CAT were apparent only with the cotransfection of a Pit-1 expression vector. These results taken together indicate that the two CREs in the chinook salmon GH gene are functionally associated with the cAMP-dependent pathway and that their promoter activity is dependent on the presence of Pit-1

Structure and regulation of the luteinizing hormone receptor gene.

Studies of the mechanisms controlling the expression of the rat luteinizing hormone receptor gene were pursued by characterization of the gene structure and identification of regulatory protein binding domains in the 5'-non-coding region of the gene and of 3' non-coding functional domains responsible for generation of the major mRNA forms. The coding region of the rat LHR gene contains 10 introns and 11 exons, of which the first 10 exons comprise the hormone binding extracellular domain and exon 11, the seven transmembrane/G protein coupling module. Several alternative spliced variants of the LHR were identified that conform to deletions of complete and/or partial exons. Within the 6.2 kb of the 3'-non-coding region, two functional LHR pA domains (H1) and (H2) produce two sets of major mRNA transcripts, each coding for both holoreceptor and the form B splice variant. The H1 pA domain is unique to LHR and may represent a recombinant insertion domain. The functional efficiency of each pA domain is related to the specific pA signals, distal downstream elements, and tissue-specific factors. A TATA-less promoter region is present within the 173 bp 5'flanking region of the gene, with Initiator (Inr) elements at transcriptional start sites. Transcription is dependent on the binding of the Sp1 protein at two Sp1 domains that each contribute equally to transcript initiation. Promoter activity is regulated by at least three additional DNA domains, R (-1266 to -1307 bp), C-box (-42 to -73 bp) and M1 (-24 to -42 bp) that bind multiple trans-factors in a tissue-specific manner. Basal promoter activity is enhanced by a functional M1 domain in LHR-expressing mouse Leydig tumor cells (MLTC) but not in non-expressing CHO cells. C-box binding factors either inhibit promoter activity or block inhibition through overlapping but not identical DNA binding domains that carry AP-2 and NF-1 elements. Removal of the AP-2 element within the C-box results in MLTC-specific transcriptional activation that may involve an MTLC M1/C-box interaction. In addition, competition for C-box factors by an upstream regulatory element (R) that is only inhibitory in CHO cells, indicates that both C-box binding factors compete for this upstream (R) domain in a tissue-specific manner. Competition between the inhibitory and neutral DNA binding factors within both upstream (R) and promoter domains (C-box) could provide a mechanism for the control of LH receptor gene expression in gonadal cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Isolation and characterization of two novel rat ovarian lactogen receptor cDNA species.

Two novel lactogen receptor cDNA clones (2.1 and 1.2 kb) were isolated from a rat ovarian cDNA library. Nucleotide sequence of the 2.1 kb clone codes for a 610 aa receptor (nonglycosylated mol. wgt. 66,000 D) with an extracellular domain, a transmembrane region and an intracellular domain, and exhibited significant overall similarity with the rat liver receptor (310 aa) and both rabbit mammary and human hepatoma receptors (616 and 622 aa). However, the ovarian lactogen receptor sequence contains a unique cytoplasmic domain of 110 aa and consensus sequences for both a tyrosine phosphorylation site and an ATP/GTP type A binding site, and thus has potential for signal transduction and mitogenic activity. The 1.2 kb clone codes for a truncated binding form of 150 aa that is identical with the ovarian long form over only the first 130 residues, and lacks the transmembrane region. Differences between long and short forms of the ovarian lactogen receptors and the truncated liver species may result from alternative splicing. The prolactin holoreceptor gene(s) has the potential for producing several receptor subtypes that differ in tissue-specific expression, size, compartmentalization and mode of signal transduction, and may subserve the divergent functions of prolactin in its several target cells.