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Puttaswamy Manjunath

Biochimie et spermatozoïdes

Professeur sous octroi titulaire

Faculté de médecine - Département de médecine

puttaswamy.manjunath@umontreal.ca

Secondary numbers: 514 252-3562 (Travail 1) 514 252-3430 (Télécopieur)

Profile

Research expertise

Biochemical characterization and physiological role(s) of proteins from the male reproductive tract:

In mammals, sperm emerging from the male reproductive tract are incapable of fertilizing egg; however, they acquire this ability during their journey in the female reproductive tract. This prerequisite conditioning is called capacitation and it is one of the key events that regulate fertility. A part of this process involves loss or modification of surface components acquired by sperm during epididymal maturation and their contact with seminal plasma. We have isolated and characterized a family of proteins from bovine seminal plasma (BSP), which are added to sperm during ejaculation. Our studies have demonstrated that these proteins are essential for capacitation and are ubiquitous in mammals. Sequences homologous to BSP proteins have been identified in human and mouse genomes. Two homologous cDNA sequences in mouse and one in human have been cloned and their specific expression (mRNA) in epididymis has been shown. To study the functions, mouse and human BSP homologous proteins have been expressed in bacteria and purified. It has been shown that these proteins have several binding characteristics in common with their homologs previously studied and may also promote sperm capacitation. We are now interested in whether the deletion of these proteins in mouse (knock-out mouse) may have an effect on fertility and whether this protein could be a cause of infertility or subfertility in men. These studies may lead to a better understanding of the mechanisms involved in fertilization and identification of an important factor for human fertility.Mechanism of sperm protection by egg yolk and milk:Over the past 70 years, egg-yolk and milk have been routinely used in both liquid semen extenders and those used to cryopreserve sperm. However, the mechanism by which egg yolk and milk protect sperm during liquid storage or from freezing damage is unknown. Thus, our laboratory is studying the mechanisms involved in sperm protection by milk and egg yolk. We discovered that a group of phospholipid-binding proteins (PL-BP), which are detrimental to sperm, are added to sperm at ejaculation. Interestingly, these detrimental factors bind caseins/whey proteins and low-density lipoproteins found in milk and egg yolk respectively. This interaction appears to reduce lipid loss from the sperm membrane, thereby preventing membrane damage during storage and preserving the sperm functions (motility, viability and acrosomal integrity). In future studies we would like to further characterize the interaction between PL-BPs and milk/egg yolk components and develop novel sperm storage medium for commercial application.

Affiliations and responsabilities

Research affiliations

Research units

Membre

Affiliated institutions

  • CIUSSS de l'Est-de-l'Île-de-Montréal – Hôpital Maisonneuve-Rosemont (HMR)

Teaching and supervision

Student supervision

Theses and dissertation supervision (Papyrus Institutional Repository)

2019

Knockout mouse model generated by CRISPR technology to study the function of BSP proteins on male fertility in vivo

Graduate : Eskandari Shahraki, Marzieh
Cycle : Doctoral
Grade : Ph. D.
2018

Binder of SPerm protein interference in sperm-egg interaction

Graduate : Heidari Vala, Hamed
Cycle : Master's
Grade : M. Sc.
2015

Rôle de protéines épididymaires humaines et murines dans les fonctions spermatiques

Graduate : Plante, Geneviève
Cycle : Doctoral
Grade : Ph. D.
2011

Étude du mécanisme de protection des spermatozoïdes de mammifères par le lait

Graduate : Lusignan, Marie-France
Cycle : Doctoral
Grade : Ph. D.

Projects

Research projects

2017 - 2024

Réseau Québecois en Reproduction (RQR)

Lead researcher : Derek Boerboom
Funding sources: FRQNT/Fonds de recherche du Québec - Nature et technologies (FQRNT)
Grant programs: PVXXXXXX-(RS) Programme de regroupements stratégiques
2017 - 2023

Mechanism of mammalian sperm protection by extender components and development of novel extenders free of products of animal origin

Lead researcher : Puttaswamy Manjunath
Funding sources: CRSNG/Conseil de recherches en sciences naturelles et génie du Canada (CRSNG)
Grant programs: PVX20965-(RGP) Programme de subvention à la découverte individuelle ou de groupe
2013 - 2019

BINDER OF SPERM (BSP) GENES AND PROTEINS : ROLE OF HUMAN AND MOUSE BSP PROTEINS IN SPERM FUNCTION AND FERTILIZATION

Lead researcher : Puttaswamy Manjunath , Frédérick Antoine Mallette
Funding sources: IRSC/Instituts de recherche en santé du Canada
Grant programs: PVXX5647-Subvention de fonctionnement incluant les subventions de fonctionnement programmatiques
2016 - 2018

Mechanism of mammalian sperm protection by extender components and development of novel extenders free of products of animal origin

Lead researcher : Puttaswamy Manjunath
Funding sources: CRSNG/Conseil de recherches en sciences naturelles et génie du Canada (CRSNG)
Grant programs: PVX20965-(RGP) Programme de subvention à la découverte individuelle ou de groupe
2016 - 2018

A microcalorimetry system to define the biochemical parameters of molecular interactions

Lead researcher : El Bachir Affar
Funding sources: CRSNG/Conseil de recherches en sciences naturelles et génie du Canada (CRSNG)
Grant programs: PVXXXXXX-(OIR) Outils et d'instruments de recherche (OIR) -1 -(de 7 001 $ à 150 000 $)
2004 - 2015

MAMMALIAN SPERM PRESERVATION : MECHANISM SPERM PROTECTION BY MILK AND DEVELOPMENT OF NOVEL EXTENDERS

Lead researcher : Puttaswamy Manjunath
Funding sources: CRSNG/Conseil de recherches en sciences naturelles et génie du Canada (CRSNG)
Grant programs: PVX20965-(RGP) Programme de subvention à la découverte individuelle ou de groupe
2009 - 2013

MAMMALIAN SPERM PRESERVATION: MECHANISM SPERM PROTECTION BY MILK AND DEVELOPMENT OF NOVEL EXTENDERS

Lead researcher : Puttaswamy Manjunath
2009 - 2013

DILUTERS OR EXTENDERS FOR MAMMALIAN SPERM PROCESSING AND PRESERVATION

Lead researcher : Puttaswamy Manjunath
2008 - 2012

INSIGHTS INTO THE MECHANISMS UNDERLYING FERTILITY: ROLE OF NOVEL PHOSPHOLIPID-BINDING PROTEINS IN SPERM FUNCTION

Lead researcher : Puttaswamy Manjunath

Outreach

Publications and presentations

Disciplines

  • Biochemistry

Areas of expertise

  • Nucleic Acids
  • Cell
  • Chromosome (Living Organisms)
  • Enzymes and Proteins
  • Gene (Living Organisms)
  • Biological and Biochemical Mechanisms
  • Bioactive Molecules