147 EFFECT OF OVULATORY FOLLICLE DIAMETER ON THE OOCYTE TRANSCRIPTOME IN BEEF COWS

2016 ◽  
Vol 28 (2) ◽  
pp. 203
Author(s):  
S. E. Dickinson ◽  
J. A. Green ◽  
T. W. Geary ◽  
K. G. Pohler ◽  
G. A. Bridges ◽  
...  

Inadequate oocyte competence is a potential explanation for reduced pregnancy rates and(or) embryonic/fetal mortality when small dominant follicles are induced to ovulate prematurely with gonadotropin releasing hormone (GnRH). Our hypothesis was that the physiological status of an ovulatory follicle has a direct effect on competence of the oocyte and resulting embryo. The objective was to determine if the transcriptome of oocytes differ depending on whether they are collected from small or large dominant follicles following a GnRH-induced gonadotropin surge. Suckled beef cows (n = 350) were pre-synchronized with a 5-day CIDR protocol. Following pre-synchronization, GnRH1 was administered on Day –9, prostaglandin F on Day –2, GnRH2 (to initiate the ovulatory process) on Day 0, and dominant follicles were transvaginally aspirated on Day 1 before follicular rupture. On Day 0, cows were divided into small (<11.7 mm; no oestrus expression), or large (>12.5 mm; no oestrus expression) groups based on dominant follicle diameter. Oocytes were individually collected after aspiration, and RNA was later extracted from pools of 4 oocytes (n = 6 oocyte pools from both small and large follicles) and sequenced on an Illumina HiSEqn 2000 (single reads, 100 bases; Illumina Inc., San Diego, CA, USA). The sequences were tiled against a ~23 500 member bovine transcript reference obtained from the National Center for Biotechnology Information (http://www.ncbi.nlm.nih.gov/). Tiling to target transcripts required a minimum match of 50 bases with at least 96% identity. Tiling counts were displayed as reads per kilobase of transcript per million mapped reads (RPKM) values, which were obtained by correcting for the length of each target (in kb) and the number of total tiled reads (in millions). Differences between groups were defined by two-tailed t-test and gene lists were selected based on P-values <0.02. Numerous differences in transcript abundance were characterised between oocytes from small and large dominant follicles. Follistatin-like 5 expression was increased (P < 0.02) in oocytes collected from large dominant follicles compared with oocytes collected from small dominant follicles. Several genes were associated with the ubiquitin pathway (e.g. ubiquitin conjugating enzyme, ubiquitin like protein-7) and were up-regulated (P < 0.02) in oocytes from large versus small dominant follicles. In addition, 4 members of the zinc finger protein family were up-regulated (P < 0.02) and 4 members were down-regulated (P < 0.02) in oocytes from large compared with small dominant follicles. In summary, some of the genes that were highly differentially regulated in bovine oocytes between small and large dominant follicles included members of the zinc finger and ubiquitin pathways, which may reflect differences in transcriptional regulation and protein turnover, respectively, between oocytes collected from large and small follicles. Study was supported by AFRI Grant no. 2013–67015–21076 from the USDA National Institute of Food and Agriculture (Washington, DC).

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 893
Author(s):  
Sarah E. Moorey ◽  
Jenna M. Monnig ◽  
Michael F. Smith ◽  
M. Sofia Ortega ◽  
Jonathan A. Green ◽  
...  

Small dominant follicle diameter at induced ovulation, but not at spontaneous ovulation, decreased pregnancy rate, fertilization rate, and day seven embryo quality in beef cows. We hypothesized that the physiological status of the follicle at GnRH-induced ovulation has a direct effect on the transcriptome of the Cumulus-Oocyte complex, thereby affecting oocyte competence and subsequent embryo development. The objective of this study was to determine if the transcriptome of oocytes and associated cumulus cells (CC) differed among small (≤11.7 mm) and large follicles (≥12.7 mm) exposed to a GnRH-induced gonadotropin surge and follicles (11.7–14.0 mm) exposed to an endogenous gonadotropin surge (spontaneous follicles). RNA sequencing data, from pools of four oocytes or their corresponding CC, revealed 69, 94, and 83 differentially expressed gene transcripts (DEG) among oocyte pools from small versus large, small versus spontaneous, and large versus spontaneous follicle classifications, respectively. An additional 128, 98, and 80 DEG were identified among small versus large, small versus spontaneous, and large versus spontaneous follicle CC pools, respectively. The biological pathway “oxidative phosphorylation” was significantly enriched with DEG from small versus spontaneous follicle oocyte pools (FDR < 0.01); whereas the glycolytic pathway was significantly enriched with DEG from CC pools obtained from large versus small follicles (FDR < 0.01). These findings collectively suggest that altered carbohydrate metabolism within the Cumulus-Oocyte complex likely contributes to the decreased competency of oocytes from small pre-ovulatory follicles exposed to an exogenous GnRH-induced gonadotropin surge.


2012 ◽  
Vol 41 (4) ◽  
pp. 1004-1008 ◽  
Author(s):  
Luiz Francisco Machado Pfeifer ◽  
Sofia del Carmen Bonilla de Souza Leal ◽  
Augusto Schneider ◽  
Eduardo Schmitt ◽  
Marcio Nunes Corrêa

2017 ◽  
Vol 29 (3) ◽  
pp. 544 ◽  
Author(s):  
Milena Lopes Oliveira ◽  
Fabio Luiz D'Alexandri ◽  
Guilherme Pugliesi ◽  
Veerle Van Hoeck ◽  
Fernando Silveira Mesquita ◽  
...  

We hypothesised that different endocrine profiles associated with pre-ovulatory follicle (POF) size would impact on uterine prostanoid pathways and thereby modulate the histotroph composition. Beef cows (n = 15 per group) were hormonally manipulated to have small (SF-SCL group) or large (LF-LCL group) pre-ovulatory follicles (POF) and corpora lutea (CL). Seven days after induction of ovulation, animals were slaughtered and uterine tissues and flushings were collected for quantification of prostanoids. The POF and CL size and the circulating progesterone concentrations at Day 7 were greater (P < 0.05) in the LF-LCL cows than in the SF-SCL group, as expected. The abundance of 5 out of 19 genes involved in prostanoid regulation was different between groups. Transcript abundance of prostaglandin F2α, E2 and I2 synthases was upregulated (P < 0.05) and phospholipase A2 was downregulated (P < 0.05) in endometrium of the LF-LCL group. No difference (P > 0.1) in prostanoid concentrations in the endometrium or in uterine flushings was detected between groups. However, prostaglandin F2α and E2 concentrations in the uterine flushings were positively correlated with the abundance of transcripts for prostaglandin endoperoxide synthase 2 (0.779 and 0.865, respectively; P < 0.002). We conclude that endometrial gene expression related to prostanoid synthesis is modulated by the peri-ovulatory endocrine profile associated with POF size, but at early dioestrus differences in transcript abundance were not reflected in changes in prostanoid concentrations in the uterine tissue and fluid.


2021 ◽  
Vol 22 (8) ◽  
pp. 4197
Author(s):  
Shiyang Zhang ◽  
Junjie Liu ◽  
Guixian Zhong ◽  
Bo Wang

The C2H2-zinc finger protein (C2H2-ZFP) is essential for the regulation of plant development and widely responsive to diverse stresses including drought, cold and salt stress, further affecting the late flavonoid accumulation in higher plants. Tea is known as a popular beverage worldwide and its quality is greatly dependent on the physiological status and growing environment of the tea plant. To date, the understanding of C2H2-ZFP gene family in Camellia sinensis [L.] O. Kuntze is not yet available. In the present study, 134 CsC2H2-ZFP genes were identified and randomly distributed on 15 chromosomes. The CsC2H2-ZFP gene family was classified into four clades and gene structures and motif compositions of CsC2H2-ZFPs were similar within the same clade. Segmental duplication and negative selection were the main forces driving the expansion of the CsC2H2-ZFP gene family. Expression patterns suggested that CsC2H2-ZFPs were responsive to different stresses including drought, salt, cold and methyl jasmonate (MeJA) treatment. Specially, several C2H2-ZFPs showed a significant correlation with the catechins content and responded to the MeJA treatment, which might contribute to the tea quality and specialized astringent taste. This study will lay the foundations for further research of C2H2-type zinc finger proteins on the stress responses and quality-related metabolites accumulation in C. sinensis.


2012 ◽  
Vol 87 (Suppl_1) ◽  
pp. 492-492
Author(s):  
Ky G. Pohler ◽  
Michael F. Smith ◽  
Emma M. Jinks ◽  
Fernanda M. Abreu ◽  
Crystal A. Roberts ◽  
...  

2017 ◽  
Author(s):  
◽  
Jenna Marie Monnig

Gonadotropin releasing hormone (GnRH)-induced ovulation of small dominant follicles decreased pregnancy rates and increased late embryonic/fetal mortality in postpartum beef cows, which could be caused by inadequate oocyte competence and(or) maternal environment. Previous studies revealed that dominant follicle size at GnRHinduced ovulation in beef cows may affect oocyte competence, as higher fertilization rates and higher embryo quality were achieved as dominant follicle diameter at insemination increased. In addition, higher pregnancy rates and increased concentrations of circulating preovulatory estradiol and postovulatory progesterone were observed in recipient cows induced to ovulate large compared to small dominant follicles, which may affect the establishment of pregnancy. The objectives of the current study were to determine the effects of preovulatory follicle size and physiological status on the cumulus cell transcriptome (Experiment 1) and determine the effects of preovulatory follicle size and steroidogenic capacity (i.e. concentrations of circulating estradiol) on the dominant follicle wall transcriptome collected before the preovulatory gonadotropin surge (Experiment 2). In Experiment 1, ovulation was synchronized in suckled beef cows by administering an injection of GnRH on d-9, prostaglandin F2a (PG) on d-2, and a second injection of GnRH on d0. The dominant follicle was trans-vaginally aspirated on d1 and cumulus-oocyte complexes (COC) were collected. The cumulus cells were removed from the oocytes and assigned to one of the following follicle classifications based on follicle diameter and estrus expression: small (n=6; less than 11.7mm; no estrus expression), large (n=6; greater than 12.5 mm; no estrus expression), or spontaneous (n=5; 11.6-13.9 mm; estrus expression and endogenous gonadotropin surge). RNA was extracted from cumulus cells collected from pools of four oocytes and sequenced before being aligned to the Bos taurus genome (UMD3.1). When comparing the cumulus cell transcriptome of small versus large preovulatory follicles, 430 transcripts were more abundant at a false discovery rate (FDR) less than 0.10 in small follicles and 454 were more abundant in large follicles. The glycolytic pathway was enriched in the cumulus cells of large follicles compared to small follicles. In the small versus spontaneous preovulatory follicle comparison, 597 transcripts were more abundant in small follicles and 1012 transcripts were more abundant in spontaneous follicles. The steroid biosynthesis pathway (i.e. cholesterol synthesis) was enriched in the cumulus cells of spontaneous compared to small follicles. In the large versus spontaneous preovulatory follicle comparison, 541 transcripts were more abundant in cumulus cells from large follicles and 951 were more abundant in cumulus cells from spontaneous follicles. In summary, a greater abundance of transcripts encoding for members of the glycolytic pathway in large follicles and transcripts encoding for members of the steroid biosynthesis pathway in the cumulus cells of spontaneous compared to small follicles indicate that oocytes from small follicles may be less competent. Preovulatory follicle development was synchronized in Experiment 2 by administering GnRH on d-9 and PG on d-2 to non-lactating beef cows. The ovaries were harvested at slaughter 48 hr after PG (d0) and the dominant follicle collected. RNA was extracted from approximately half of the follicle wall and sequenced. Cows were divided into two classifications based on dominant follicle diameter at collection: small (n=4; less than 11.5 mm) and large (n=7; greater than 12.5 mm). Nine transcripts were more abundant in small follicles, and two transcripts were more abundant in large follicles. No significant pathways were found. The same 11 follicle walls were also divided into two classifications based on concentration of serum estradiol at 48 hr after PG: low (n=6; less than 4.0 pg/ml) and high (n=5; greater than or equal to 4.0 pg/ml). In the low estradiol classification, 281 transcripts were more abundant in the follicle wall and 40 were more abundant in the follicle wall of the high estradiol classification. No significant pathways were found. Transcripts were analyzed with PANTHER to find significant gene ontology (GO) terms. Differentially abundant transcripts in low estradiol follicles were more highly associated with mitosis, chromosome segregation, and regulation of biological processes. In summary, a small number of transcripts were differentially abundant in the follicle wall of small versus large dominant follicles prior to the preovulatory gonadotropin surge and no specific pathways were identified that might provide insight into how the physiological maturity of a dominant follicle can affect pregnancy rate. Comparisons made between follicle walls from follicles with low or high serum estradiol found a larger number of transcripts were more highly abundant in the low estradiol follicles, possibly indicating that a higher level of transcription is taking place in the low estradiol follicles, and therefore are less mature.


2018 ◽  
Vol 30 (1) ◽  
pp. 145
Author(s):  
J. B. Borges ◽  
A. B. Machado ◽  
E. Pradebon ◽  
M. Dias ◽  
M. Bernardi ◽  
...  

Complete luteolysis is essential for pregnancy success in beef cows submitted to fixed-time AI (FTAI) protocols. The objective of this study was to evaluate the effect of prostaglandin F (PGF) administration on Day 7 compared with Day 8 of an FTAI protocol on serum progesterone (P4) concentration, oestrus behaviour, ovulatory follicle (OF) diameter, and pregnancy per AI (P/AI). A total of 469 nonlactating Angus cows [with corpus luteum (CL), n = 359 or without CL, n = 110], body condition score 2.9 ± 0.2 (1 to 5 scale), maintained on pasture were used. Cows received a 1-g progesterone-releasing intravaginal device (Reproneo; GlobalGen, Jaboticabal, Brazil) and 2 mg of oestradiol benzoate i.m. (Syncrogen; GlobalGen) on Day 0. On Day 7, animals were randomly allocated into 2 groups. Cows were treated with 500 μg of sodium cloprostenol, IM (Inducio; GlobalGen), on Day 7 (PGF7, n = 238) or Day 8 (PGF8, n = 231). Then, P4 devices were removed and 0.5 mg of oestradiol cypionate, IM (Cipion; GlobalGen) was injected in all females on Day 8. The FTAI was performed 48 to 52 h after P4 device removal. Females had sacral region painted with appropriate paint (TELL TAIL, GEA, Hamilton New Zealand) on Day 8 to detect expression of oestrus. Transrectal ultrasonography (7.5-MHz linear transducer, MediSono P3V, Wilmington, DE, USA) was performed on Day 0 to detect presence of CL, on Day 10 to measure OF diameter, and on Day 40 to diagnose pregnancy. Blood samples were collected on Days 8 and 10 to measure P4 serum concentration by radioimmunoassay. Oestrus behaviour and pregnancy rate were analysed as binary outcomes using logistic regression (Proc GLIMMIX, SAS; SAS Institute Inc., Cary, NC, USA). OF diameter and P4 concentration were submitted to analysis of variance (Proc GLIMMIX, SAS). The oestrus manifestation was greater (odds ratio = 2.9; P = 0.0002) in females of PGF7 group (91.6%; 218/238) than PGF8 group (78.8%; 182/231). The P/AI of cows that exhibited oestrus was 60.2% (241/400) v. 39.1% (27/69), resulting in higher chance (odds ratio = 2.4) of pregnancy associated with oestrus behaviour (P = 0.0014). Diameter of the OF did not differ (P = 0.0881) between PGF7 (11.7 mm) and PGF8 (11.3 mm). The P/AI was higher (P = 0.0034) for PGF7 (63.9%, 152/238) v. PGF8 (50.2%, 116/231). In group PGF7, P4 on Day 8 did not differ between pregnant (1.7 ng mL−1) and nonpregnant (1.9 ng mL−1) females. However, group PGF8 pregnant females had lower P4 concentration (2.6 ng mL−1) on Day 8 (P = 0.0005) than nonpregnant (3.4 ng mL−1) females. On Day 10, P4 did not differ between treatments (PGF7 = 0.11 ng mL−1 v. PGF8 = 0.09 ng mL−1) and did not affect fertility (P = 0.2515). According to results, OF diameter and P4 concentration on Day 10 were not influenced by the day of PGF administration; however, earlier PGF injection resulted in higher oestrus behaviour and increased fertility.


1996 ◽  
Vol 270 (4) ◽  
pp. G613-G618 ◽  
Author(s):  
C. Khoo ◽  
N. A. Hallquist ◽  
D. A. Samuelson ◽  
R. J. Cousins

Cysteine-rich intestinal protein (CRIP) is a double zinc finger (LIM domain) protein that is developmentally regulated but has an unknown function. CRIP is highly expressed in the intestine, but expression is low in liver. To determine if CRIP expression is regulated under altered physiological status, we used CCl4-induced injury as a model to produce hepatic injury and systemic effects associated with inflammation. Since CRIP is a zinc finger protein and zinc decreases the hepatic response to CCl4, the effect of supplemental dietary zinc (300 mg/kg diet) was also examined. Our results show that this supplemental level of dietary zinc did not affect the index of hepatic injury (plasma alanine aminotransferase), indicating zinc did not have a protective effect. Liver CRIP mRNA increased with CCl4 and CRIP protein was shown by immunohistochemistry to be localized in hepatocytes near the vascular supply. In the intestine, CCl4 caused a transient decrease in CRIP mRNA, but supplemental dietary zinc treatment prevented this decrease. These current results show that CRIP expression changes in response to cellular damage due to acute hepatic injury and are consistent with a functional role for CRIP in proliferation, differentiation, or turnover.


Metabolites ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 623
Author(s):  
Casey C. Read ◽  
Lannett Edwards ◽  
Neal Schrick ◽  
Justin D. Rhinehart ◽  
Rebecca R. Payton ◽  
...  

Induced ovulation of small pre-ovulatory follicles reduced pregnancy rates, embryo survival, day seven embryo quality, and successful embryo cleavage in beef cows undergoing fixed-time artificial insemination. RNA-sequencing of oocytes and associated cumulus cells collected from pre-ovulatory follicles 23 h after gonadotropin-releasing hormone (GnRH) administration to induce the pre-ovulatory gonadotropin surge suggested reduced capacity for glucose metabolism in cumulus cells of follicles ≤11.7 mm. We hypothesized that the follicular fluid metabolome influences metabolic capacity of the cumulus-oocyte complex and contributes to reduced embryo cleavage and quality grade observed following induced ovulation of small follicles. Therefore, we performed a study to determine the correlation between pre-ovulatory follicle diameter and follicular fluid metabolome profiles in lactating beef cows (Angus, n = 130). We synchronized the development of a pre-ovulatory follicle and collected the follicular contents approximately 20 h after GnRH administration. We then performed ultra-high performance liquid chromatography—high resolution mass spectrometry (UHPLC-HRMS) metabolomic studies on 43 follicular fluid samples and identified 38 metabolites within pre-ovulatory follicles of increasing size. We detected 18 metabolites with a significant, positive correlation to follicle diameter. Individual and pathway enrichment analysis of significantly correlated metabolites suggest that altered glucose and amino acid metabolism likely contribute to reduced developmental competence of oocytes when small pre-ovulatory follicles undergo induced ovulation.


Development ◽  
2000 ◽  
Vol 127 (6) ◽  
pp. 1243-1251 ◽  
Author(s):  
B. Chen ◽  
E. Harms ◽  
T. Chu ◽  
G. Henrion ◽  
S. Strickland

Mutations in grauzone or cortex cause abnormal arrest in Drosophila female meiosis. We cloned grauzone and identified it as a C2H2-type zinc finger transcription factor. The grauzone transcript is present in ovaries and at later developmental stages. A Grauzone-GFP fusion protein is functional and localizes to nuclei of both nurse cells and follicle cells during oogenesis. Three lines of evidence indicate that grauzone and cortex interact: reducing cortex function enhanced the grauzone mutant phenotype; cortex transcript abundance is reduced in the absence of grauzone function and Grauzone protein binds to the cortex promoter. These results demonstrate that activation of cortex transcription by grauzone is necessary for the completion of meiosis in Drosophila oocytes, and establish a new pathway that specifically regulates the female meiotic cell cycle.


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