scholarly journals Sperm transport and retention at the fertilization site is orchestrated by a chemical guidance and oviduct movement

Reproduction ◽  
2012 ◽  
Vol 143 (5) ◽  
pp. 587-596 ◽  
Author(s):  
H A Guidobaldi ◽  
M E Teves ◽  
D R Uñates ◽  
L C Giojalas
Keyword(s):  
Evolutionary Adaptation ◽  
Sperm Transport ◽  
Working Model ◽  
Combined Action ◽  
Oviductal Fluid ◽  
Rabbit Spermatozoa

In mammals, only a few spermatozoa arrive at the fertilization site. During the last step in the journey to the egg, apart from their self-propulsion, spermatozoa may be assisted by oviduct movement and/or a guidance mechanism. The proportion of rabbit spermatozoa that arrive at the fertilization site was determined under in vivo conditions, in which either the ovulation products (secreting chemoattractants) and/or the oviduct movement (causing the displacement of the oviductal fluid) was inhibited. When only one of these components was inhibited, sperm transport to the fertilization site was partially reduced. However, when both the ovulation products and the oviduct movement were inhibited, almost no spermatozoa arrived at the fertilization site. The results suggest that spermatozoa are transported to and retained at the fertilization site by the combined action of a chemical guidance and the oviduct movement. A working model is proposed to explain how these two mechanisms may operate to transport spermatozoa to the fertilization site, probably as an evolutionary adaptation to maximize the chance of fertilizing an egg.

Release of soluble peptidoglycan from growing conococci: demonstration of anhydro-muramyl-containing fragments

1980 ◽  
Vol 29 (3) ◽  
pp. 914-925 ◽  
Author(s):  
R K Sinha ◽  
R S Rosenthal
Keyword(s):  
Group Analysis ◽  
Gel Filtration ◽  
Diaminopimelic Acid ◽  
Host Interactions ◽  
Peptide Moiety ◽  
Kd Values ◽  
Monomer Fraction ◽  
Combined Action ◽  
Beta Elimination

Previous analysis of soluble peptidoglycan (PG) fragments released by exponentially growing gonococci implicated the combined action of both hexosaminidase and amidase activities in PG turnover. Current studies further characterized PG fragments which were labeled in the glycan with D-glucosamine and in the peptide moiety with meso-diaminopimelic acid of L- and D-alanine. Labeled PG fragments were isolated by gel filtration and characterized on the bases of (i) KD values, (ii) free amino group analysis using fluorodinitrobenzene, (iii) borohydride reduction, (iv) alkali-catalyzed beta-elimination, (v) paper chromatography in various solvents, (vi) electrophoretic mobility at various pH values, (vii) digestibility by Charonia lampas glycosidases, and (viii) content of labeled D- and L-alanine. A set of well-characterized PG fragments was used as standards. The monomer fraction (the major extracellular product) was found to contain two components. Most (about 80%) appeared to be N-acetylglucosaminyl-beta-1 leads to 4-1,6-anhydro-N-acetylmuramyl-L-ala-D-glu-meso-diaminopimelic acid; the remainder was the corresponding disaccharide tetrapeptide containing a C-terminal D-alanine. An unusual feature of these products was the presence of the anhydro-muramyl (non-reducing) ends, reflecting the activity of a gonococcal transglycosylase, and the near absence of products containing detectable reducing ends. Otherwise, the structures of the monomer fragments were typical of those expected for a gram-negative bacterium (chemotype I). The corresponding peptide-cross-linked dimer and the free disaccharide also contained nonreducing ends, exclusively. Free peptides (products of amidase activity) consisted of both tripeptide and tetrapeptide. In summary, all gonococci examined appear to possess an unusual transglycosylase activity which contributes to the release of soluble PG fragments containing nonreducing, anhydro-muramyl ends. The release of these fragments in vivo might be a unique aspect of gonococci-host interactions.

scholarly journals Colonization of gut microbiota by plasmid-carrying bacteria is facilitated by evolutionary adaptation to antibiotic treatment

2021 ◽  
Author(s):  
Peng Zhang ◽  
Daqing Mao ◽  
Huihui Gao ◽  
Liyang Zheng ◽  
Zeyou Chen ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Bacterial Species ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Evolutionary Adaptation ◽  
Antibiotic Exposure ◽  
Resistance Protein ◽  
K 12

AbstractMultidrug-resistant plasmid-carrying bacteria are of particular clinical concern as they could transfer antibiotic resistance genes to other bacterial species. However, little is known whether evolutionary adaptation of plasmid-carrying bacteria after long-term antibiotic exposure could affect their subsequent colonization of the human gut. Herein, we combined a long-term evolutionary model based on Escherichia coli K-12 MG1655 and the multidrug-resistant plasmid RP4 with in vivo colonization experiments in mice. We found that the evolutionary adaptation of plasmid-carrying bacteria to antibiotic exposure facilitated colonization of the murine gut and subsequent plasmid transfer to gut bacteria. The evolved plasmid-carrying bacteria exhibited phenotypic alterations, including multidrug resistance, enhanced bacterial growth and biofilm formation capability and decreased plasmid fitness cost, which might be jointly caused by chromosomal mutations (SNPs in rpoC, proQ, and hcaT) and transcriptional modifications. The upregulated transcriptional genes, e.g., type 1 fimbrial-protein pilus (fimA and fimH) and the surface adhesin gene (flu) were likely responsible for the enhanced biofilm-forming capacity. The gene tnaA that encodes a tryptophanase-catalyzing indole formation was transcriptionally upregulated, and increased indole products participated in facilitating the maximum population density of the evolved strains. Furthermore, several chromosomal genes encoding efflux pumps (acriflavine resistance proteins A and B (acrA, acrB), outer-membrane protein (tolC), multidrug-resistance protein (mdtM), and macrolide export proteins A and B (macA, macB)) were transcriptionally upregulated, while most plasmid-harboring genes (conjugal transfer protein (traF) and (trbB), replication protein gene (trfA), beta-lactamase TEM precursor (blaTEM), aminoglycoside 3'-phosphotransferase (aphA) and tetracycline resistance protein A (tetA)) were downregulated. Collectively, these findings demonstrated that evolutionary adaptation of plasmid-carrying bacteria in an antibiotic-influenced environment facilitated colonization of the murine gut by the bacteria and plasmids.

scholarly journals Sperm Proteome after Interaction with Reproductive Fluids in Porcine: From the Ejaculation to the Fertilization Site

2020 ◽  
Vol 21 (17) ◽  
pp. 6060 ◽  
Author(s):  
Chiara Luongo ◽  
Leopoldo González-Brusi ◽  
Paula Cots-Rodríguez ◽  
Mª José Izquierdo-Rico ◽  
Manuel Avilés ◽  
...  
Keyword(s):  
Seminal Plasma ◽  
Proteome Analysis ◽  
Interacting Proteins ◽  
Sperm Transport ◽  
Two Fluids ◽  
Boar Sperm ◽  
Uterine Fluid ◽  
Proteome Changes ◽  
Oviductal Fluid

Ejaculated sperm are exposed to different environments before encountering the oocyte. However, how the sperm proteome changes during this transit remains unsolved. This study aimed to identify proteomic changes in boar sperm after incubation with male (seminal plasma, SP) and/or female (uterine fluid, UF; and oviductal fluid, OF) reproductive fluids. The following experimental groups were analyzed: (1) SP: sperm + 20% SP; (2) UF: sperm + 20% UF; (3) OF: sperm + 20% OF; (4) SP + UF: sperm + 20% SP + 20% UF; and (5) SP+OF: sperm + 20% SP + 20% OF. The proteome analysis, performed by HPLC-MS/MS, allowed the identification of 265 proteins. A total of 69 proteins were detected in the UF, SP, and SP + UF groups, and 102 proteins in the OF, SP, and SP + OF groups. Our results showed a higher number of proteins when sperm were incubated with only one fluid than when they were co-incubated with two fluids. Additionally, the number of sperm-interacting proteins from the UF group was lower than the OF group. In conclusion, the interaction of sperm with reproductive fluids alters its proteome. The description of sperm-interacting proteins in porcine species after co-incubation with male and/or female reproductive fluids may be useful to understand sperm transport, selection, capacitation, or fertilization phenomena.

scholarly journals Expression of an exogenous interleukin 6 gene in human Epstein Barr virus B cells confers growth advantage and in vivo tumorigenicity.

1990 ◽  
Vol 172 (1) ◽  
pp. 61-68 ◽  
Author(s):  
G Scala ◽  
I Quinto ◽  
M R Ruocco ◽  
A Arcucci ◽  
M Mallardo ◽  
...  
Keyword(s):  
B Cell ◽  
Interleukin 6 ◽  
Epstein Barr Virus ◽  
Constitutive Expression ◽  
Soft Agar ◽  
Malignant Phenotype ◽  
Barr Virus ◽  
Combined Action ◽  
Epstein Barr

The biological role of interleukin 6 (IL-6) molecules in human B cell tumorigenesis was studied by using an episomal expression vector, pHEBoSV-IL6, to introduce stably the human IL-6 gene into human Epstein Barr virus (EBV)-transformed B lymphoblasts. The gene was present in the IL-6-transfected cells in a high copy number and was efficiently expressed, resulting in the secretion of consistent levels of IL-6 molecules. The constitutive expression of the IL-6 gene led to an altered pattern of growth and to a malignant phenotype, as shown by clonogenicity in to an altered pattern of growth and to a malignant phenotype, as shown by clonogenicity in soft agar cultures and tumorigenicity in nude mice. These data suggest that the combined action of EBV, which exerts an immortalizing function, and of the growth-promoting activity of IL-6 molecules, can give rise to fully transformed B cell tumors in immunodeficient subjects.

293. Gametes alter the oviductal secretory proteome in vivo

2005 ◽  
Vol 17 (9) ◽  
pp. 124
Author(s):  
A. S. Georgiou ◽  
E. Sostaric ◽  
C. H. Wong ◽  
A. P. L. Snijders ◽  
P. C. Wright ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Recognition System ◽  
Sperm Viability ◽  
Affinity Tag ◽  
Two Dimensional Gel Electrophoresis ◽  
Surgical Interventions ◽  
Gamete Recognition ◽  
Boar Semen ◽  
Oviductal Fluid

We sought to identify altered oviductal protein secretions in response to the presence of gametes in the oviduct in vivo at the time of ovulation. Experiments were designed to compare oviductal fluid from a gamete-stimulated oviduct to a non-gamete-stimulated oviduct within the same animal. Clips were introduced at the infundibulum of both oviducts to prevent oocytes from entering the oviducts and one uterine horn was cut to prevent sperm access to that oviduct. Sows were artificially inseminated the next day with diluted boar semen. Control sows that had undergone the same surgical procedures were inseminated with diluent (no sperm). The day after insemination oviducts were removed and oviductal fluid was collected. Two-dimensional gel electrophoresis, isotope coded affinity tag (ICAT) technology and LC-ESI-MS/MS were used to identify and quantify proteins regulated by presence of spermatozoa in the oviduct. To identify the effect of oocyte presence in the oviduct, only one oviduct was clipped at the infundibulum. This prevented oocytes from entering that oviduct. Sows were monitored for ovulation using sonography and 24 h after ovulation oviducts were removed and oviductal fluid was analysed as described above. Results indicated that in vivo, the oviduct responded to the presence of spermatozoa and oocytes by altering its secretory proteomic profile. Our surgical interventions were not responsible for any of these alterations. Many of the identified proteins are known to be involved in oocyte maturation, maintenance of sperm viability, fertilisation, and embryonic development. Our findings suggest that the oviduct responds to gametes by providing specific molecules to sustain, regulate or enhance events preceding and during fertilisation, and early embryonic development. Furthermore, it seems a gamete recognition system is present in the oviduct. Supported by grants from the BBSRC and Sygen International PLC.

scholarly journals PKAc-directed interaction and phosphorylation of Ptc is required for Hh signaling inhibition in Drosophila

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Jialin Fan ◽  
Yajie Gao ◽  
Yi Lu ◽  
Wenqing Wu ◽  
Shuo Yuan ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Kinase Activity ◽  
Functional Assays ◽  
Working Model ◽  
Inhibitory Function ◽  
Hh Signaling ◽  
Signaling Activation

Abstract Ptc is a gatekeeper to avoid abnormal Hh signaling activation, but the key regulators involved in Ptc-mediated inhibition remain largely unknown. Here, we identify PKAc as a key regulator required for Ptc inhibitory function. In the absence of Hh, PKAc physically interacts with Ptc and phosphorylates Ptc at Ser-1150 and -1183 residues. The presence of Hh unleashes PKAc from Ptc and activates Hh signaling. By combining both in vitro and in vivo functional assays, we demonstrate that such Ptc–PKAc interaction and Ptc phosphorylation are both important for Ptc inhibitory function. Interestingly, we further demonstrate that PKAc is subjected to palmitoylation, contributing to its kinase activity on plasma membrane. Based on those novel findings, we establish a working model on Ptc inhibitory function: In the absence of Hh, PKAc interacts with and phosphorylates Ptc to ensure its inhibitory function; and Hh presence releases PKAc from Ptc, resulting in Hh signaling activation.

Retinoic Acid in Association with Tin-Metalloporphyrins Influences Heme Metabolism in vivo in Rats

1999 ◽  
Vol 69 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Chandra ◽  
Aneja ◽  
Sharma ◽  
Tiwari
Keyword(s):  
Retinoic Acid ◽  
Toxic Metabolite ◽  
Concurrent Administration ◽  
Biliverdin Reductase ◽  
Amino Levulinic Acid ◽  
Combined Action ◽  
Tin Protoporphyrin ◽  
Substantial Decline ◽  
Marked Suppression

In the current study we report the perturbation of key enzymes of the heme metabolic pathway, i.e. delta-amino levulinic acid synthase, heme oxygenase and biliverdin reductase, in vivo by administration of retinoic acid (RA) and retinoic acid in association with tin-metalloporphyrins, viz., tin-protoporphyrin (SnPP) and tin-mesoporphyrin (SnMP) in the liver, spleen, heart and lung of rats. RA at a dosing regimen of 50,000 I.U. stimulated splenic ALA-S activity, whereas co-administration of tin-metalloporphyrins with RA antagonised the RA mediated induction of ALA-S. In the other tissues viz., liver, heart and lung our results showed a diminution of ALA-S activity on RA administration, the level of repression was further attenuated when tin-metalloporphyrins were co-administered with RA. This marked suppression of ALA-S brought forth by concurrent administration of RA and tin-metalloporphyrins is suggestive of the beneficial effect of this formulation in acute attacks of porphyria, similar to heme. Furthermore, our results emphasize that the combined dosing of RA with tin-metalloporphyrins leads to a substantial decline in bilirubin levels due to a profound inhibition of HMOX in the probed tissues. The features of the combined action of RA and tin-metalloporphyrins in vivo lead to a substantial suppression of formation of the potentially toxic metabolite bilirubin, and the enhancement of disposal of the untransformed substrate (heme) of the enzyme that is inhibited. These results define some of the characteristics of a therapeutically useful formulation and represent a new therapeutic approach for the amelioration and management of hyperbilirubinemia.

scholarly journals The retinoblastoma protein binds to a family of E2F transcription factors.

1993 ◽  
Vol 13 (12) ◽  
pp. 7813-7825 ◽  
Author(s):  
J A Lees ◽  
M Saito ◽  
M Vidal ◽  
M Valentine ◽  
T Look ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Retinoblastoma Protein ◽  
Cdna Clones ◽  
Wild Type ◽  
Recognition Sites ◽  
Number Of Genes ◽  
Combined Action ◽  
E2f Transcription Factors

E2F is a transcription factor that helps regulate the expression of a number of genes that are important in cell proliferation. Recently, several laboratories have isolated a cDNA clone that encodes an E2F-like protein, known as E2F-1. Subsequent characterization of this protein showed that it had the properties of E2F, but it was difficult to account for all of the suggested E2F activities through the function of this one protein. Using low-stringency hybridization, we have isolated cDNA clones that encode two additional E2F-like proteins, called E2F-2 and E2F-3. The chromosomal locations of the genes for E2F-2 and E2F-3 were mapped to 1p36 and 6q22, respectfully, confirming their independence from E2F-1. However, the E2F-2 and E2F-3 proteins are closely related to E2F-1. Both E2F-2 and E2F-3 bound to wild-type but not mutant E2F recognition sites, and they bound specifically to the retinoblastoma protein in vivo. Finally, E2F-2 and E2F-3 were able to activate transcription of E2F-responsive genes in a manner that was dependent upon the presence of at least one functional E2F binding site. These observations suggest that the E2F activities described previously result from the combined action of a family of proteins.

Forskolin effect on the cryosurvival of in vitro-produced bovine embryos in the presence or absence of fetal calf serum

Zygote ◽  
2012 ◽  
Vol 22 (2) ◽  
pp. 146-157 ◽  
Author(s):  
Daniela Martins Paschoal ◽  
Mateus José Sudano ◽  
Midyan Daroz Guastali ◽  
Rosiára Rosária Dias Maziero ◽  
Letícia Ferrari Crocomo ◽  
...  
Keyword(s):  
Culture Medium ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Similar Rate ◽  
Bovine Embryos ◽  
Embryo Survival ◽  
Vitrification Solution ◽  
Oviductal Fluid

SummaryThe objective of this study was to assess the viability and cryotolerance of zebu embryos produced in vitro with or without the addition of fetal calf serum (FCS) and forskolin (F). Embryos produced in vivo were used as a control. Presumptive zygotes were cultured in modified synthetic oviductal fluid supplemented with amino acids (SOFaa), bovine serum albumin (BSA) and with (2.5%) or without (0%) FCS. On day 6 of growth, the embryos from each group were divided into treatments with or without 10 μM F to induce embryonic lipolysis, comprising a total of four experimental groups: 2.5% FCS, 0% FCS, 2.5% + F and 0% + F. For vitrification, embryos were exposed to vitrification solution 1 (5 M EG (ethylene glycol)) for 3 min and then transferred to vitrification solution 2 (7 M EG, 0.5 M galactose solution and 18% (w/v) Ficoll 70) before being introduced to liquid nitrogen. The presence of FCS in the culture medium resulted in the production of embryos with a similar rate of damaged cells compared with in vivo-produced embryos. After vitrification, the 2.5% FCS group had a significantly higher rate of damaged cells when compared with the other groups (P < 0.05). The results of this experiment indicated that the omission of FCS and the addition of forskolin do not have deleterious effect on embryo production rates. In addition, embryos produced in the presence of FCS had greater sensitivity to cryopreservation, but this effect was reversed when forskolin was added to the medium, which improved embryo survival without affecting embryo development and quality after vitrification.

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