Inheritance of genomic regions and genes associated with number of oocytes and embryos in Gir cattle through daughter design.

Over the past decades, daughter designs, including genotyped sires and their genotyped daughters, have been used as an approach to identify quantitative trait loci (QTL) related with economic traits. The aim of this study was to identify genomic regions inherited by Gir sire families and genes associated with number of viable oocytes (VO), total number of oocytes (TO) and number of embryos (EMBR) based on a daughter design approach. In total, 15 Gir sire families were selected. The number of daughters per family ranged from 26 to 395, which were genotyped with different SNP panels and imputed to the Illumina BovineHD BeadChip (777K) and had phenotypes for oocyte and embryo production. Daughters had phenotypic data for VO, TO, and EMBR. The search for QTL was performed through Genome-Wide Association Study (GWAS) based on genomic best linear unbiased prediction (gBLUP). QTL were found for each trait among and within families based on the top 10 genomic windows with the greatest genetic variance. For EMBR, genomic windows identified among families were located on BTA4, BTA5, BTA6, BTA7, BTA8, BTA13, BTA16 and BTA17, and they were most frequent on BTA7 within families. For VO, genomic windows were located on BTA2, BTA4, BTA5, BTA7, BTA17, BTA21, BTA22, BTA23 and BTA27 among families, being most frequent on BTA8 within families. For TO, top 10 genomic windows were identified on BTA2, BTA4, BTA5, BTA7, BTA17, BTA21, BTA22, BTA26 and BTA27, being most frequent on BTA7 and BTA8 within families. Considering all results, the greatest number of genomic windows was found on BTA7, where VCAN, XRCC4, TRNAC-ACA, HAPLN1 and EDIL3 genes were identified in the common regions. In conclusion, 15 Gir sire families with 26 to 395 daughters per family with phenotypes for oocyte and embryo production helped to identify the inheritance of several genomic regions, especially on BTA7, where EDIL3, HAPLN1 and VCAN candidate genes were associated with number of oocytes and embryos in Gir cattle families.

Development of tetra-primer ARMS-PCR protocol to genotype the prolactin receptor SNP 39136666 and assessment of this SNP in Brazilian locally adapted cattle breeds / [Desenvolvimento de protocolo de tetra-primer ARMS- PCR para genotipagem do SNP 39136666 do receptor da prolactina e avaliação desse SNP em raças bovinas brasileiras localmente adaptadas]

As raças taurinas de origem ibérica Limonero e Carora (Bos primigenius taurus) possuem o fenótipo de pelo curto, liso e com baixa densidade folicular, o que confere a esses animais maior tolerância térmica e melhor produtividade em regiões quentes. Diferentes mutações associadas a esse fenótipo foram descritas no gene do receptor de prolactina PRLR, localizado no cromossomo bovino BTA20. Uma mutação recentemente encontrada é a substituição do nucleotídeo C por T, SNP 39136666 (p. R497*), no exon 11, que gera um códon de parada e, consequentemente, uma menor isoforma desse receptor. Neste trabalho, desenvolveu-se um protocolo rápido e de baixo custo para detecção desse SNP, utilizando-se a técnica de tetra-primer ARMS-PCR. Assim, foi possível detectar essa mutação nas raças brasileiras de origem ibérica localmente adaptadas: Caracu, Crioulo Lageano, Mocho Nacional e Pantaneiro. O alelo T foi mais frequente na raça Caracu (80%), enquanto o alelo C foi mais frequente na raça Crioulo Lageano (84%). Essa simples metodologia pode ser usada para genotipar esse SNP e ajudar na aplicação dessas informações moleculares em programas de melhoramento focados na tolerância térmica em bovinos taurinos e seus mestiços.(AU)

Laparoscopic Liver Resection: A South American Experience with 2887 Cases.

BACKGROUND: Laparoscopic liver resections (LLR) have been increasingly performed in recent years. Most of the available evidence, however, comes from specialized centers in Asia, Europe and USA. Data from South America are limited and based on single-center experiences. To date, no multicenter studies evaluated the results of LLR in South America. The aim of this study was to evaluate the experience and results with LLR in South American centers. METHODS: From February to November 2019, a survey about LLR was conducted in 61 hepatobiliary centers in South America, composed by 20 questions concerning demographic characteristics, surgical data, and perioperative results. RESULTS: Fifty-one (83.6%) centers from seven different countries answered the survey. A total of 2887 LLR were performed, as follows: Argentina (928), Brazil (1326), Chile (322), Colombia (210), Paraguay (9), Peru (75), and Uruguay (8). The first program began in 1997; however, the majority (60.7%) started after 2010. The percentage of LLR over open resections was 28.4% (4.4-84%). Of the total, 76.5% were minor hepatectomies and 23.5% major, including 266 right hepatectomies and 343 left hepatectomies. The conversion rate was 9.7%, overall morbidity 13%, and mortality 0.7%. CONCLUSIONS: This is the largest study assessing the dissemination and results of LLR in South America. It showed an increasing number of centers performing LLR with the promising perioperative results, aligned with other worldwide excellence centers.

Quantificação do DNA e genotipagem de biópsias de embriões bovinos Gir e Girolando produzidos in vitro / DNA quantification and genotyping of biopsies obtained from Gyr and Girolando in vitro produced bovine embryos

A biópsia embrionária associada à genotipagem permite a obtenção de informações genômicas antes mesmo da transferência dos embriões. Neste estudo, foram avaliadas amostras biopsiadas de blastocistos bovinos transferidos para receptoras (n=47), sob a hipótese de que a raça (Gir ou Girolando), o estádio embrionário (blastocisto ou blastocisto expandido) e a competência para estabelecimento de prenhez (positiva ou negativa) afetariam a quantidade e a qualidade do DNA da amostra obtida. O DNA foi extraído, amplificado, quantificado por eletroferograma e genotipado. O parâmetro call rate (CR) foi adotado para mensurar a qualidade da genotipagem. Obteve-se concentração de DNA de 86,07±171,66ng/µL e CR 0,73±0,17. O CR não variou em função da quantidade de DNA nas amostras. As variáveis raça e estádio embrionário não influenciaram a concentração de DNA, nem o CR. Houve efeito da prenhez sobre o CR (P=0,0187), mas, como houve maior CR nas amostras provenientes do grupo prenhez negativa, não foi possível associar esse parâmetro à qualidade embrionária. Concluiu-se que a raça e a qualidade embrionária não afetam os parâmetros aqui estudados em amostras embrionárias, ou seja, embriões com maiores chances de implantação não refletem alta qualidade nas amostras de biópsia genotipadas.(AU)

Embryo biopsy associated with genotyping allows genomic information before embryo transfer. In this study, blastocyst biopsy samples from embryos transferred to recipients (n= 47) were evaluated, under the hypothesis that breed (Gyr or Girolando), embryonic stage (blastocyst or expanded blastocyst) and competence to establish pregnancy (positive or negative) would affect the quantity and DNA quality of samples. DNA was extracted, amplified, quantified by electropherogram and genotyped. The parameter call rate (CR) was used to measure the quality of genotyping. DNA concentration of 86.07±171.66ng/µl, and CR 0.73±0.17 was obtained. CR did not vary according to the amount of DNA in the samples. The variables breed and embryonic stage had no influence on DNA concentration or CR. There was pregnancy effect on the CR (P= 0.0187), but since there was a higher CR in the samples from the negative pregnancy group, it was not possible to associate this parameter with the embryonic quality. We conclude that the breed and embryo quality do not affect the evaluated parameters in embryonic samples. Embryos with higher chances of implantation do not reflect high quality in embryo biopsy genotyped samples.(AU)

Differential expression of LHCGR and its isoforms is associated to the variability in superovulation responses of Gir cattle.

The aim of this study was to evaluate the pattern of expression of LHCGR isoforms in Gir heifers characterized as good (10.3 ±â€¯1.2 ova/embryos per flush, n = 5) or poor responders (1.1 ±â€¯0.3 ova/embryos per flush, n = 5) to superovulation protocols. In both groups, an adapted ultrasound-guided follicular aspiration system was used to collect granulosa cells from 8 mm follicles formed either during a synchronized, non-stimulated follicular wave (no stimulation control, NS) or on the fourth day of a superovulation protocol (SOV) induced with 200 IU of pFSH. The recovered follicular fluid was centrifuged and granulosa cells were washed with NaCl 0.9% and kept in RNAlater®. RNA extraction was performed using a commercial RNeasy Micro Kit and eluted samples were quantified and reverse transcribed using the commercial Superscript III kit. cDNA samples were amplified by real-time PCR using a primer to target LH/hCG receptor gene - not selective for LHCGR isoforms (total LHCGR) - and four sets of isoforms selective primers (S1, S10, S10 + 11, and S11). Analyses were performed using the REST software and expression levels are shown as mean ± SEM. Under physiological conditions (NS), poor responders had a higher expression of total LHCGR (4.9 ± 1.7 fold-change, P < 0.01) as well as isoforms S10, S11 and S10 + 11, compared to good responders. In both phenotypes, superovulation down-regulated total LHCGR expression (-0.5 ± 0.2 and -0.9 ± 0.0 for good and poor responders, respectively; P < 0.05). However, in poor responders the exogenous FSH treatment up-regulated the S10 (2.4 ± 2.0; P < 0.05), S10 + 11 (3.8 ± 3.2; P < 0.01), and S1 isoforms (1.8 ± 1.3; P < 0.05), compared to good responders We conclude that down-regulation of total LHCGR, associated to up-regulation of their inactive isoforms, may have compromised follicle development and thus contributed to the low efficiency of superovulation in heifers with a poor responder phenotype.

Analysis of Defense-Related Gene Expression in Citrus Hybrids Infected by Xylella fastidiosa.

Resistance to Xylella fastidiosa was evaluated in 264 hybrids of crosses between Murcott tangor (Citrus reticulata × Citrus sinensis) and Pera sweet orange (C. sinensis) under field conditions. Uninfected hybrids were grafted with buds collected from Pera sweet orange plants infected with X. fastidiosa, forming a plant with two scions (i.e., hybrid branches and Pera sweet orange branches). From these plants, we chose 10 genotypes with three biological replicates. We evaluated gene expression, bacterial multiplication, and citrus variegated chlorosis (CVC) symptom development in both scions. X. fastidiosa was not detected in most hybrid scions and none showed disease symptoms. In contrast, all Pera sweet orange scions were infected with X. fastidiosa and expressed symptoms of CVC. We quantified the expression of 12 defense-related genes by qPCR comparing resistant to susceptible scions. We suggest that some of these genes are involved in resistance of the hybrids to X. fastidiosa, since their expression was significantly higher in the resistant hybrid scions than in tolerant hybrids and scions originated from CVC symptomatic Pera sweet orange buds. However, we note that these data should be interpreted carefully, as the plant genotypes tested are related but necessarily distinct (hybrids of C. reticulata and C. sinensis, in relation to a C. sinensis control). A principal component analysis revealed a relationship between the expression of these genes and hybrid scions, and between scions that originated from infected buds and the presence of the bacteria and plant symptoms. Multiyear field trials are necessary to develop plant resistance to X. fastidiosa. While the experimental design used here had limitations, it allowed us to identify a set of genes potentially involved in Citrus sp. resistance to this pathogen. Future work on the role of these genes in plant defenses to X. fastidiosa infection is necessary to confirm their importance in the displayed resistance phenotype.

A novel approach for quantitative harmonization in PET.

Positron emission tomography (PET) imaging allows for measurement of activity concentrations of a given radiotracer in vivo. The quantitative capabilities of PET imaging are particularly important in the context of monitoring response to treatment, where quantitative changes in tracer uptake could be used as a biomarker of treatment response. Reconstruction algorithms and settings have a significant impact on PET quantification. In this work we introduce a novel harmonization methodology requiring only a simple cylindrical phantom and show that it can match the performance of more complex harmonization approaches based on phantoms with spherical inserts. Resolution and noise measurements from cylindrical phantoms are used to simulate the spherical inserts from NEMA image quality phantoms. An optimization algorithm was used to find the optimal smoothing filters for the simulated NEMA phantom images to identify those that best harmonized the PET scanners. Our methodology was tested on seven different PET models from two manufacturers installed at five institutions. Our methodology is able to predict contrast recovery coefficients (CRCs) from NEMA phantoms with errors within ±5.2% for CRCmax and ±3.7% for CRCmean (limits of agreement = 95%). After applying the proposed harmonization protocol, all the CRC values were within the tolerances from EANM. Quantitative harmonization in compliance with the EARL FDG-PET/CT accreditation program is achieved in a simpler way, without the need of NEMA phantoms. This may lead to simplified scanner harmonization workflows more accessible to smaller institutions.

Duplicated or Hybridized Peptide Functional Domains Promote Oral Homeostasis.

Proteins that have existed for millions of years frequently contain repeats of functional domains within their primary structure, thereby improving their functional capacity. In the evolutionary young statherin protein contained within the in vivo-acquired enamel pellicle (AEP), we identified a single functional domain (DR9) located within the protein N-terminal portion that exhibits a higher affinity for hydroxyapatite and more efficient protection against enamel demineralization compared to other native statherin peptides. Thus, we tested the hypothesis that multiplication of functional domains of naturally occurring pellicle peptides amplifies protection against enamel demineralization. In addition, a specific amino acid sequence from histatin 3 (RR-14) was introduced to the hybrid peptides for further testing. Enamel specimens were sectioned to 150-µm thickness and randomly grouped as follows: DR9, DR9-DR9, DR9-RR14, statherin, histatin 1, or distilled water (control). After submersion for 2 h at 37°C, the specimens were placed in 2 mL demineralization solution for 12 d at 37°C. Upon sample removal, the remaining solution was subjected to colorimetric assays to determine the amount of calcium and phosphate released from each specimen. DR9-DR9 amplified protection against enamel demineralization when compared to single DR9 or statherin. Notably, the hybrid peptide DR9-RR14 demonstrated relatively strong protection when the antimicrobial property of these peptides was tested against Candida albicans and Streptococcus mutans. DR9-RR14 was able to maintain 50% of the antifungal activity compared with RR14 for C. albicans and similar values of S. mutans killing activity. This study has pioneered the functional exploration of the natural peptide constituents of the AEP and their evolution-inspired engineered peptides. The knowledge obtained here may provide a basis for the development of stable (proteinase-resistant) synthetic peptides for therapeutic use against dental caries, dental erosion, and/or oral candidiasis.

Accuracy of genomic predictions in Gyr (Bos indicus) dairy cattle.

Genomic selection may accelerate genetic progress in breeding programs of indicine breeds when compared with traditional selection methods. We present results of genomic predictions in Gyr (Bos indicus) dairy cattle of Brazil for milk yield (MY), fat yield (FY), protein yield (PY), and age at first calving using information from bulls and cows. Four different single nucleotide polymorphism (SNP) chips were studied. Additionally, the effect of the use of imputed data on genomic prediction accuracy was studied. A total of 474 bulls and 1,688 cows were genotyped with the Illumina BovineHD (HD; San Diego, CA) and BovineSNP50 (50K) chip, respectively. Genotypes of cows were imputed to HD using FImpute v2.2. After quality check of data, 496,606 markers remained. The HD markers present on the GeneSeek SGGP-20Ki (15,727; Lincoln, NE), 50K (22,152), and GeneSeek GGP-75Ki (65,018) were subset and used to assess the effect of lower SNP density on accuracy of prediction. Deregressed breeding values were used as pseudophenotypes for model training. Data were split into reference and validation to mimic a forward prediction scheme. The reference population consisted of animals whose birth year was ≤2004 and consisted of either only bulls (TR1) or a combination of bulls and dams (TR2), whereas the validation set consisted of younger bulls (born after 2004). Genomic BLUP was used to estimate genomic breeding values (GEBV) and reliability of GEBV (R2PEV) was based on the prediction error variance approach. Reliability of GEBV ranged from ∼0.46 (FY and PY) to 0.56 (MY) with TR1 and from 0.51 (PY) to 0.65 (MY) with TR2. When averaged across all traits, R2PEV were substantially higher (R2PEV of TR1 = 0.50 and TR2 = 0.57) compared with reliabilities of parent averages (0.35) computed from pedigree data and based on diagonals of the coefficient matrix (prediction error variance approach). Reliability was similar for all the 4 marker panels using either TR1 or TR2, except that imputed HD cow data set led to an inflation of reliability. Reliability of GEBV could be increased by enlarging the limited bull reference population with cow information. A reduced panel of ∼15K markers resulted in reliabilities similar to using HD markers. Reliability of GEBV could be increased by enlarging the limited bull reference population with cow information.

Red Sindhi cattle in Brazil: population structure and distribution.

The Red Sindhi cattle breed was imported to Brazil in small numbers. Nowadays, the herds of this breed are distributed in the Northeast, Southeast and Midwest regions of the country. In this study, DNA samples of animals originating from 15 herds in the Northeast and Southeast regions have been analyzed to obtain the ancestry proportions, and to gain a better understanding of the current population structure of this breed in Brazil. Samples were genotyped using three different single nucleotide polymorphism (SNP) marker panels. Those markers have been used with the approach of unsupervised hierarchical clustering of individuals, and consequently, the ancestry of the population was divided into six different subpopulations. Three of those ancestry subpopulations were identified to be present in various different herds, while the other three were restricted to only one or two herds each. One of those herds has been kept isolated for more than 30 years, and it was identified to contain two almost exclusive subpopulations. To avoid important losses in the genetic diversity within the Red Sindhi breed in Brazil, we recommend the identification of superior sires from every subpopulation in the establishment of a breeding program for this breed.

Intrafollicular oestradiol production, expression of the LH receptor (LHR) gene and its isoforms, and early follicular deviation in Bos indicus.

The aim of the present study was to characterise the roles of intrafollicular oestradiol production and granulosa cell (GC) expression of the LH receptor (LHR) gene and its isoforms during follicular deviation in Bos indicus. Follicular wave emergence was synchronised in heifers from a Bos taurus dairy (Holstein; n=10) and a B. indicus dairy breed (Gir; n=10). Follicles were aspirated individually at sizes corresponding to the periods of predeviation, deviation and postdeviation. Intrafollicular oestradiol (IF-E2) and progesterone (IF-P4) concentrations were determined in the follicular fluid (FF) by radioimmunoassay, and relative expression of P450 aromatase (CYP19A1) and LHR forms was evaluated in GC using real-time quantitative-polymerase chain reaction. Despite differences in the size of the dominant follicle at deviation, changes in CYP19A1 expression and IF-E2 concentrations were similar in follicles of the same diameter in both breeds. A peak in total LHR expression occurred after follicular deviation in association with low expression of LHR isoforms. The results suggest that regulation of LHR function by sequential changes in the expression pattern of LHR isoforms may play a role in the early deviation of the dominant follicle, as observed in B. indicus breeds.

Total Laparoscopic Reversal ALPPS.

BACKGROUND: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) allows R0 resection even for patients with extremely small future liver remnants. The ALPPS procedure was initially described for two-stage right trisectionectomy. Reversal ALPPS is a denomination in which the future liver remnant is the right posterior section of the liver. PATIENT: A 42-year-old woman with colorectal metastases in all segments except segment 1 underwent chemotherapy with objective response and was referred for surgical treatment. The computed tomography (CT) scan showed a predominance of metastases in the left liver and in the right anterior section. The right posterior section had three metastases. The plan was to perform a laparoscopic reversal ALPPS (left portal vein ligation combined with in situ splitting in a two-stage left trisectionectomy). TECHNIQUE: Three metastases in the right posterior section were resected, followed by liver partition and left portal vein ligature. The CT scan showed a 70 % increase in the future liver remnant. The second stage constituted left trisectionectomy. At laparoscopy after division of adhesions, the left Glissonian pedicle was divided with an endostapler. A stapler also was used to transect the left and middle hepatic veins, and the specimen was removed through a suprapubic incision. The operative times were respectively 5 and 3 h, and the patient was discharged on days 4 and 5, respectively. No blood transfusion or intensive care unit stay was necessary. At this writing, the patient shows no evidence of the disease 18 months after the procedure. CONCLUSIONS: Reversal laparoscopic ALPPS is feasible and safe. Laparoscopy is useful for decreasing blood loss and optimizing visualization during liver transection.

Genome wide selection in Citrus breeding.

Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seqTM (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

Alternative approach for carious tissue removal in primary teeth.

BACKGROUND: Minimally-invasive techniques for the management of carious dental tissue has been well documented. This study aimed to report on the clinical and radiographic response after partial caries removal on left mandibular primary second molar. CASE REPORT: A 6-year-old boy sought treatment because of pain in the left mandibular primary second molar. The tooth had a deep caries lesion on the occlusal surface, with loss of enamel structure and dentine proximity with the pulp confirmed by periapical radiograph. According to the clinical and radiographic diagnosis, partial caries removal was the treatment of choice. Calcium hydroxide cement was used as pulp capping material. FOLLOW-UP: In this case report, partial caries removal showed satisfactory clinical and radiographic outcomes after 18-month following-up period. CONCLUSION: Partial caries removal only is applicable when properly indicated. However, further clinical studies with longer following-up periods are necessary.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in colorectal liver metastasis: the radiologist's perspective.

PURPOSE: Hepatic resection is the only potentially curative treatment for patients with colorectal liver metastasis (CRLM). Many multidisciplinary approaches, including the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure, have been proposed to increase the resectability rate in these patients. ALPPS is the most recently described staged liver resection technique, representing an advantageous strategy to induce a rapid and marked increase in the future liver remnant (FLR) volume. The aim of this article is to describe the radiological evaluation of this procedure and its variation. METHODS: This retrospective study included 9 patients with CRLM who underwent the ALPPS procedure. Abdominal imaging studies were reviewed, with an emphasis on a rational radiological approach. The number of liver metastases, the FLR volume (pre- and postportal vein ligation), anatomical variations, potential pitfalls related to disease progression, and postoperative complications were evaluated. RESULTS: The types of hepatic resection included 4 classical ALPPS cases, 3 right ALPPS variations, and 2 left ALPPS variations. The mean FLR volume calculated in the initial evaluation was 453 mL (213-790 mL). Following the first surgery, the mean FLR volume increased to 634 mL (410-957 mL), which indicated a mean volume increase of 181.1 mL (95% CI 149.7-212.5 mL; p < 0.001) and a mean absolute volume increase of 48% (19%-88%). CONCLUSION: The ALPPS procedure is an emerging form of two-stage hepatectomy. In this context, radiologists should provide crucial preoperative and perioperative information that may change surgical planning and contribute to an improvement in the oncologic outcome.

Polymorphisms and alternative splicing of the luteinizing hormone receptor of dairy cattle.

The aim of this study was to screen for variability in the luteinizing hormone/choriogonadotropin receptor (LHCGR) and to determine the occurrence of LHCGR mRNA isoforms in two dairy breeds of cattle. Granulosa cells from dominant ovarian follicles were recovered from 16 Gir and 16 Holstein cows, and total RNA was extracted. Complementary DNA was synthesized and PCR was used to generate amplicons for sequencing. Chromatograms were evaluated, and multiple sequences were aligned and analyzed for the presence of polymorphisms, allele frequency, polymorphic information content (PIC), and Hardy-Weinberg equilibrium (HWE). Twenty-one single nucleotide polymorphisms (SNPs) were identified in LH receptor mRNA. Seventeen SNPs were identified in Gir cattle (seven exclusively), and 14 were found in Holstein cattle (four exclusively). Seven of the 21 polymorphisms found did not alter which amino acid was translated. Eight SNPs caused a change to an amino acid in a different chemical group. Classification of SNPs according to PIC values identified 12 as being highly informative in Gir cattle and five in Holstein. Eight SNPs deviated from HWE in Gir compared with 11 in Holstein, and eight in both breeds. Two isoforms were also identified, one in exon 1, which lacks 30 nucleotides beginning at position 118, and the other in exon 10. Taken together, these data show that LHCGR in dairy cattle breeds has a high frequency of polymorphism and exists in multiple isoforms resulting from alternative splicing.

In situ Effect of Chewing Gum with and without CPP-ACP on Enamel Surface Hardness Subsequent to ex vivo Acid Challenge.

The erosion-protective effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is controversial. This study aimed to investigate the ability of CPP-ACP chewing gum to prevent a single event of erosive demineralization in situ. Bovine enamel blocks (n = 120) were randomly assigned to 3 phases according to the baseline surface hardness: phase I (PI) - chewing gum with CPP-ACP, phase II (PII) - chewing gum without CPP-ACP, and control phase (PIII) - salivary effect without stimulation (no gum). Nineteen volunteers participated in this study during 3 crossover phases of 2 h. In PI and PII, the volunteers wore intraoral palatal appliances for 120 min and chewed a unit of the corresponding chewing gum for the final 30 min. In the control phase the volunteers wore the appliance for 2 h, without chewing gum. Immediately after intraoral use, the appliances were extraorally immersed in a cola drink for 5 min to promote erosive demineralization. The percentage of surface hardness loss was calculated. The data were analyzed by ANOVA models and Tukey's test. Lower enamel hardness loss was found after the use of chewing gum with CPP-ACP (PI: 32.7%) and without CPP-ACP (PII: 33.5%) compared to the salivary effect without stimulation (PIII: 39.8%) (p < 0.05). There was no difference between PI and PII (p > 0.05). The results suggest that the use of chewing gum immediately before an erosive demineralization can diminish enamel hardness loss. However, the presence of CPP-ACP in the chewing gum cannot enhance this protective effect.