Marco Mello - Academia.edu (original) (raw)

Papers by Marco Mello

Reproduction

Cattle are generally considered a monovular species; however, recently a bovine high fecundity al... more Cattle are generally considered a monovular species; however, recently a bovine high fecundity allele, termed the Trio allele, was discovered. Carriers of Trio have an elevated ovulation rate (3 to 5) while half-sibling noncarriers are monovular. Carriers of the Trio allele have overexpression in granulosa cells of SMAD6, an inhibitor of oocyte-derived regulators of granulosa cell proliferation and differentiation. In experiment 1, follicle size was tracked for each follicle during a follicular wave. Follicle growth rate was greater before vs after follicle deviation in both carriers and noncarriers. Additionally, follicle growth rate was consistently less in carriers vs noncarriers. In experiment 2, we collected granulosa cells from follicles before and after deviation for evaluation of granulosa cell gene expression. Granulosa cell proliferation was less in carriers vs noncarriers and after vs before follicle deviation (decreased expression of cell cycle genes CCNB1 and CCNA2). Th...

Reproduction in Domestic Animals

(A) Wild-type, (B) heterozygous and (C) homozygous fibroblasts immune-stained for fibril... more (A) Wild-type, (B) heterozygous and (C) homozygous fibroblasts immune-stained for fibrillin-1 (scale bars 50 µm). In contrast to the elaborate network of immunoreactive fibrillin-1 seen in control lines, heterozygous and homozygous cell cultures show a diffuse pattern of immunoreactive material. (D) Representative field at higher magnification to show intracellular deposition of mutant protein (scale bar 25 µm).</p

(A) Scheme of Fbn1 targeting. From top to bottom, fibrillin1 protein ... more (A) Scheme of Fbn1 targeting. From top to bottom, fibrillin1 protein with the internally deleted region (residues 770–1042); schematic representation of the corresponding Fbn1 gene region with the probes (I and III) used in the Southern-blot analysis, and the sizes of BamHI (b) and HindIII (h) fragments; and targeted Fbn1mgΔloxPneo allele with the neoR flanked by lox-P sequences (triangles). (B) Southern blot of genomic DNA from correctly targeted ES clone digested with BamHI, and hybridized to probe I. (C) sequence of the cDNA from the Fbn1mgΔloxPneo allele showing the junction of exons 18 and 25; (D) Heredogram of founder heterozygotes in a mixed 129/Sv/CD-1 background. Hetreozygotes were phenotypically normal until the F3, where one severely affected heterozygote was found (arrow), whose X-ray is shown. (E) Relative quantification of total Fbn1 mRNA levels in wild-type (WT), heterozygous (HE) and homozygous (HO) fetal fibroblasts by Real Time RT-PCR analysis (P<0.05).</p

(A) Real-time RT-PCR analysis of wild-type (WT – left panel) and mutant (right panel) &l... more (A) Real-time RT-PCR analysis of wild-type (WT – left panel) and mutant (right panel) Fbn1 alleles in heterozygous 129/Sv animals. Individual animals are represented by different colored bars. For each animal three technical replicas were performed. Note that, despite the expression variability among different animals, the ratio between mutant and normal Fbn1 transcripts is constant. (B to D) Correlation between level of expression of total Fbn1 (Y axis) and the severity of (B) lung, (C) vascular (AWT: aortic wall thickness), and (D) skeletal phenotypes in heterozygous 129/Sv animals. Diamonds correspond to the animals represented in (A). Pearson's correlation coefficients (R) and the statistical significance (P) are shown. Note strong correlation (|R|≥0.75) between levels of total Fbn1 expression and severity of the phenotype in the three affected systems.</p

(A) Comparison of histological slides and radiography of 129/Sv heterozygotes at 3 month... more (A) Comparison of histological slides and radiography of 129/Sv heterozygotes at 3 months of age show phenotypic variation in this strain. Wild-type (+/+), asymptomatic (AS) and severely affected (SE) heterozygous mice. (B) Average mean linear intercept at 3 and 6 months of age (*P<0.42, **P<0.0006, ***P<0.006). (C) Average thickness of thoracic aortic media at 3 and 6 months of age (*P<0.33, **P<0.04, †P<0.8, ††P<0.01). (D) Average KR at 3 and 6 months (*P<0.03, **P<0.04). (MI) Mildly affected animals. The number of animals analyzed in each group (n) and the ages (3 m and 6 m represent 3 months and 6 months, respectively) are shown.</p

Theriogenology, 2018

The goal of this study was to evaluate the effect of long-acting progesterone supplementation on ... more The goal of this study was to evaluate the effect of long-acting progesterone supplementation on pregnancy rates and gestational losses in Nelore females (Bos taurus indicus) submitted to Timed Artificial Insemination (TAI). Ovulations of multiparous (n=534), primiparous (n=117) and nulliparous (n=81) Nelore females were synchronized for TAI and the day of insemination was considered D0. After TAI, the animals were allocated into three groups. Two groups received 150 mg of long acting injectable progesterone (P4) in a single dose, 5 (D = 5) or 11 (D = 11) days after TAI, resulting in the following treatments: 1) Group P4-D5 (n = 235); 2) Group P4-D11 (n = 245); and 3) Control Group (n = 252). The animals in the control group did not receive any supplementation. Pregnancy was checked by ultrasonography, 30 days after the TAI. The gestational losses were evaluated at two different periods: 1) from 30 to 60 days, and 2) from 60 to 90 days. The pregnancy rate and the gestational losses as a function of the treatments were tested by the non-parametric binomial test with 5% significance level. The pregnancy rates were different between the groups P4-D5 and Control (47 and 39%, respectively) (P <0.05), but no difference was observed in relation to the P4-D11 group. There was a difference in gestational losses from 30 to 60 days and total losses between the groups treated with P4 on the fifth day and eleventh day after TAI in relation to the control group (P = 0.0173; P=0.0454), but no difference was observed between the treatments in relation to the losses between 60 and 90 days (P ≥0.0578). Among the animals that were cycling at the beginning of the protocol, the groups supplemented with progesterone at day 5 or 11 after insemination had gestational losses significantly lower (P = 0.04) than the control group (P4-D5 = 2%; P4-D11 = 2%, control = 14%). The animals in anestrous that received supplementation 5 days after TAI had lower gestational losses (P = 0.049) compared with the other groups (P4-D5 = 3%, P4-D11=7% Control = 10%). Under the conditions of this study, the use of long-acting injectable progesterone 5 days after TAI in Nelore females increased the pregnancy rates, but when supplemented 11 days after TAI, it did not have the same effect. Also, when used 5 days after TAI, it significantly decreased gestational losses on both anestrous and cycling animals. Therefore, it may be an interesting alternative to increase reproductive and productive efficiencies.

PLoS ONE, 2010

Marfan syndrome is an autosomal dominant disease of connective tissue caused by mutations in the ... more Marfan syndrome is an autosomal dominant disease of connective tissue caused by mutations in the fibrillin-1 encoding gene FBN1. Patients present cardiovascular, ocular and skeletal manifestations, and although being fully penetrant, MFS is characterized by a wide clinical variability both within and between families. Here we describe a new mouse model of MFS that recapitulates the clinical heterogeneity of the syndrome in humans. Heterozygotes for the mutant Fbn1 allele mgD loxPneo , carrying the same internal deletion of exons 19-24 as the mgD mouse model, present defective microfibrillar deposition, emphysema, deterioration of aortic wall and kyphosis. However, the onset of a clinical phenotypes is earlier in the 129/Sv than in C57BL/6 background, indicating the existence of genetic modifiers of MFS between these two mouse strains. In addition, we characterized a wide clinical variability within the 129/Sv congenic heterozygotes, suggesting involvement of epigenetic factors in disease severity. Finally, we show a strong negative correlation between overall levels of Fbn1 expression and the severity of the phenotypes, corroborating the suggested protective role of normal fibrillin-1 in MFS pathogenesis, and supporting the development of therapies based on increasing Fbn1 expression.

Theriogenology, 2020

The aim was to develop a program for resynchronization of ovulation (ReBreed21) that allowed rein... more The aim was to develop a program for resynchronization of ovulation (ReBreed21) that allowed reinsemination of non-pregnant Bos indicus heifers every 21 d using timed AI (TAI) without the need for detection of estrus. The Rebreed21 program begins 12 d after previous TAI (Day 0) by inserting an intravaginal P4 implant (Day 12) that is removed 7 d later (Day 19) combined with treatment with 300 IU of eCG. On Day 21, early pregnancy diagnosis (Doppler PD) is performed based on CL vascularity. Nonpregnant (NP) heifers immediately received AI combined with 100 mg of GnRH. The program is replicated 12 d after second TAI to produce a breeding season (BS) of 42 d with 3 potential TAIs. Two experiments were conducted as a proof of concept for this rapid rebreeding program. In Experiment 1, 76 heifers were enrolled in ReBreed21, as explained above. In Experiment 2, 300 Nellore heifers were synchronized for 1st TAI and randomly assigned to one of two groups: ReBreed21 (n ¼ 147) or another early resynchronization procedure, Resynch14 (n ¼ 153) with P4 implant inserted 14 d after previous TAI plus 50 mg of long-acting injectable P4; 8 d later P4 implant removed (Day 22) and early Doppler PD performed; NP heifers received 150 mg of cloprostenol, 0.5 mg of ECP, and 300 IU of eCG with TAI on Day 24. In both experiments, the largest follicle (LF) was measured at each Resynch TAI. Ultrasound was later used to confirm the early Doppler PD and to determine ovulation (OV) to Resynch at 12 d after TAI in ReBreed21 (Day 33 of pregnancy) and 14 d after TAI in Resynch14 (Day 38 of pregnancy). Final PD was performed 40 d after 3rd TAI. Results for Experiment 1 were: diameter of LF 11.8 ± 0.23 mm; 88.9% OV; 20.5% false positives; 38.1% P/AI at 1st TAI; 44.4% overall P/AI for ReBreed21 TAIs; 72.3% total pregnant at end of BS. In experiment 2, Rebreed21 vs. Resynch14 were different for: diameter of LF (10.9 ± 0.17 vs. 10.0 ± 0.17 mm, P ¼ 0.0003), heifers with LF < 8.5 mm (10.2 vs. 26.4%, P ¼ 0.04), or LF ! 11 mm (50.0 vs. 37.2%, P ¼ 0.001), and P/AI at first TAI (29.3% [43/147] vs. 20.3% [31/153], P ¼ 0.074) but similar for OV (overall 86.8% [239/275], P ¼ 0.82), false positives (P ¼ 0.52) overall P/AI for Resynch TAIs (33.6 vs. 28.8%, P ¼ 0.4), and total pregnant at end of BS (58.5% [86/147] vs. 55.6% [85/153], P ¼ 0.64). In addition, median time to pregnancy was 9 d earlier (P ¼ 0.0007) for ReBreed21 than Resynch14. Thus, ReBreed21 is a novel protocol that allows earlier reinseminations than Resynch14 but with similar fertility.

Boletim de Indústria Animal, 2016

RESUMO: O objetivo deste trabalho foi avaliar o efeito do grau de assincronia da receptora sobre ... more RESUMO: O objetivo deste trabalho foi avaliar o efeito do grau de assincronia da receptora sobre a taxa de prenhez após a transferência de embriões bovinos produzidos in vitro. Foram utilizados dados da Empresa Minerembryo, localizada em Alfenas, MG, referentes a 335 novilhas mestiças receptoras, distribuídas em três grupos de acordo com o grau de assincronia: assincronia-1: o estro da receptora ocorreu um dia antes da aspiração folicular (grupo I, n=106 animais); sincronia 0: o estro da receptora ocorreu no dia da aspiração folicular (grupo II, n=119 animais) e assincronia +1: o estro da receptora ocorreu um dia após a aspiração folicular (grupo III, n=110 animais). Os resultados foram analisados pelo teste Qui-quadrado, com nível de significância de 5%. As taxas de prenhez para os grupos I, II e III foram 34,90; 35,29 e 33,63, respectivamente. Não se observou efeito (P=0,98) do grau de assincronia sobre a taxa de prenhez. Portanto, pode-se concluir que é viável a utilização de receptoras com maior grau de assincronia, melhorando o aproveitamento das mesmas em programas de produção in vitro de embriões bovinos. Palavras-chave: produção in vitro, assincronia, prenhez.

Boletim de Indústria Animal, 2015

Boletim do Instituto de Pesca Sao Paulo

This study was performed to evaluate a protocol for sperm cryopreservation of the marine shrimp L... more This study was performed to evaluate a protocol for sperm cryopreservation of the marine shrimp Litopenaeus schmitti, an important species in Brazilian commercial fisheries. No studies or protocols were found for cryopreservation of its spermatic mass. This paper provides information about the technique of semen storage based on protocols applied to other penaeids species. Two cryoprotectants, glycerol and dimetilsulfoxide (DMSO), were tested for sperm cells toxicity in two concentrations (5 and 10%), and two exposure times (10 and 30 minutes). Influence of liquid nitrogen storage in apparent sperm viability (ASV) was also tested in 1, 15 and 30 days of storage. The cryopreservation was performed in a two-step (2 and 0.5ºC min -1) freezing protocol. After freezing until the temperature -32°C, sperm mass was immersed in liquid nitrogen (-196ºC). Thus, glycerol and DMSO was not toxic to sperm in both concentrations and equilibration times. For all toxicity tests ASV was up to 79.8% af...