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. 2013 Jun 10;8(6):e65083.
doi: 10.1371/journal.pone.0065083. Print 2013.

Gamete therapeutics: recombinant protein adsorption by sperm for increasing fertility via artificial insemination

Horacio Alvarez-Gallardo  1 , Michael E Kjelland, Juan F Moreno, Thomas H Welsh Jr, Ronald D Randel, Miguel A Lammoglia, Mario Pérez-Martínez, Alma V Lara-Sagahón, A Enrique Esperón-Sumano, Salvador Romo
Affiliations

Gamete therapeutics: recombinant protein adsorption by sperm for increasing fertility via artificial insemination

Horacio Alvarez-Gallardo et al. PLoS One. .

Abstract

A decrease in fertility can have a negative economic impact, both locally and over a broader geographical scope, and this is especially the case with regard to the cattle industry. Therefore, much interest exists in evaluating proteins that might be able to increase the fertility of sperm. Heparin binding proteins (HBPs), specifically the fertility associated antigen (FAA) and the Type-2 tissue inhibitor of metalloproteinase (TIMP-2), act to favor the capacitation and acrosome reaction and perhaps even modulate the immune system's response toward the sperm. The objective of this research was to determine the effect on fertility of adding recombinant FAA (rFAA) and recombinant TIMP-2 (rTIMP-2) to bovine semen before cryopreservation for use in an artificial insemination (AI) program in a tropical environment. For this experiment, 100 crossbred (Bos taurus x Bos indicus) heifers were selected based on their estrus cycle, body condition score (BCS), of 4 to 6 on a scale of 1 to 9, and adequate anatomical conformation evaluated by pelvic and genital (normal) measurements. Heifers were synchronized using estradiol benzoate (EB), Celosil® (PGF2α) (Shering-Plough) and a controlled internal drug release (CIDR) device was inserted that contained progesterone. Inseminations were performed in two groups at random, 50 animals per group. The control group was inseminated with conventional semen. The treatment group was inseminated with semen containing rFAA (25 µg/mL) and rTIMP-2 (25 µg/mL). In the control group a 16% pregnancy rate was obtained versus a 40% pregnancy rate for the HBP treatment group, resulting in a significant difference (P = 0.0037). Given the results herein, one may conclude that the HBPs can increase fertility and could be an option for cattle in tropical conditions; however, one needs to consider the environment, nutrition, and the genetic interaction affecting the final result in whatever reproductive program that is implemented.

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Conflict of interest statement

Competing Interests: Notably, it may be perceived that a conflict of interest exists given that Sexing Technologies is a licensee of the recombinant proteins utilized in the present research. In addition, one of the co-authors, JFM, is employed by Sexing Technologies and MEK is a former employee. Personal competing interests could be perceived as several of the co-authors are friends. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials. Further, this does not alter the authors' objectivity in conducting the research and presenting the results.

Figures

Figure 1
Figure 1. Visualization of representative control and treatment sperm samples included the following: a) fertility associated antigen (FAA) antibody control sample (FAA negative) without FAA present on sperm (provided by Midland Bioproducts Corporation®) and verified after the application of fluorescein conjugated FAA antibody, b) FAA protein control sample (FAA negative, provided by Midland Bioproducts Corporation®) with fluorescein conjugated FAA recombinant protein added to sperm, c) fluorescein conjugated Type-2 tissue inhibitor of metalloproteinase (TIMP-2) antibody added to sperm, and d) fluorescein conjugated TIMP-2 protein added to sperm.
Figure 2
Figure 2. Sperm from the Brahman bull used in this study with: a) fluorescein conjugated Type-2 tissue inhibitor of metalloproteinase (TIMP-2) antibody revealing natural levels and location of TIMP-2 protein, b) fluorescein conjugated TIMP-2 recombinant protein adsorption by sperm, c) fluorescein conjugated fertility associated antigen (FAA) antibody revealing natural levels and location of FAA protein, and d) fluorescein conjugated FAA recombinant protein adsorption by sperm.
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References

    1. McCauley TC, Zhang HM, Bellin ME, Ax RL (2001) Identification of a heparin-binding protein in bovine seminal fluid as tissue inhibitor of metalloproteinases-2. Mol Reprod Dev 58: 336–341. - PubMed
    1. Harshan HM, Singh LP, Arangasamy A, Ansari MR, Kumar S (2006) Effect of buffalo seminal plasma heparin binding protein (HBP) on freezability and in vitro fertility of buffalo cauda spermatozoa. Anim Reprod Sci 93: 124–133. - PubMed
    1. Nauc V, Manjunath P (2000) Radioimmunoassays for bull seminal plasma proteins (BSP-A1/−A2, BSP-A3, and BSP 30 kilodaltons), and their quantification in seminal plasma and sperm. Biol Reprod 63: 1058–1066. - PubMed
    1. Killian GJ, Chapman DA, Rogowski LA (1993) Fertility-associated proteins in Holstein bull seminal plasma. Biol Reprod 49: 1202–1207. - PubMed
    1. Miller DJ, Winer MA, Ax RL (1990) Heparin-binding proteins from seminal plasma bind to bovine spermatozoa and modulate capacitation by heparin. Biol Reprod 42: 899–915. - PubMed

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Funding for this research came from the Texas A&M University-Conacyt Collaborative Research Grant Program, Project Nr. 2009-004: Adaptation of Biotechnologies for Reproduction of Cattle in the Tropics (2009–2010), http://vpr.tamu.edu/funding/conacyt. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Further, no individuals employed or contracted by the funders (other than the named authors) played any role in: study design, data collection and analysis, decision to publish, or preparation of the manuscript.