Why I choose

sex

Tamara Leahy

PhD student

Overview

Agriculture is a cutting-edge industry with more to it than just growing crops and milking cows.

At Uni, I became fascinated by the fact that we can improve productivity of animals by understanding

and improving their efficiency to reproduce.

I’m going to show you the vital role of sex in agriculture.

Background

I was fascinated by animals from a young age…

Photo: Tamara 6 months old, petting zoo

and became one of the few who actually ended up doing what they wanted to do at age 6

“When I grow up I am going to be an animal breeder”

Photo: Tamara 6 years, pony club

From Ponies

to Elephants

to Tigers

Riding Peow-Pong in Ko Lanta

It doesn’t get any better than this. Working with

animals all over the world.

Why is agriculture

important?

Agriculture in Australia is of cultural, environmental and economic importance

ANIMALS ARE A BIG PART OF IT

Yeah, but Kevin Rudd took all the

credit.

Did you hear the rural sector saved Australia

from recession.

Assisted reproductive

technologies in agriculture

What is the purpose?

Can’t they do it alone?

What are assisted reproductive technologies?

Assisted reproductive technology (ART) is a general term referring to methods used to achieve pregnancy by artificial or partially artificial means.

Artificial insemination

Process in which sperm are placed in the female tract to facilitate fertilisation

Collection

Intrauterine insemination

How is AI done??

Semen can be deposited directly

into the vagina, cervix or uterus

Image: www.wiki.ucalgary.ca

/

Sperm Freezing

Removes temporal and spatial (time and space) restrictions to distribution of superior genetics

This gives animal breeders more choice when selecting genetically desired traits

Image: www.isisrfc.com/cryopreservation.php

ART advantages include:

The ability to freeze semen helps to ensure the survival of rare gene pools, for example endangered species.

Image: www.messiah.edu

Australian Innovators Australia is considered to be

• ahead of competitors in the use of genetic markers and artificial insemination for breeding.

• on par with competitors in the use of DNA-based and protein-based diagnostic tests and disease treatments.

Value of Biotechnology to Australian Economy:www.daff.gov.au/__data/assets/pdf_file/0003/437601/non-gm-report.pdf

The next exciting step is being able to determine the sex of the

offspring

SEX

SELECTION

Did you know? A few animals can determine the sex of their offspring naturally but maybe we can help them all and couldn’t we do wondrous things if we did?

• Sex of crocodiles is determined by egg incubation temperature.

• Nemo or Nema? The head male clown fish will turn into a female to maintain social structure if head female dies.

Image http://scienceblogs.com

What to know more:www.genetics.com.au/factsheet/index.asp

In mammals (including ourselves)

sex is determined by

chromosomes

Males have X or Y

chromosome-bearing

sperm

Females only have X

X + X = Female

Y + X = Male

How?

• Many weird and wonderful techniques have been reported to determine the sex of offspring but the only reliable method is separation based on DNA content (X larger than Y).

• The sperm are stained and processed through a machine.

• A laser in the machine is used to differentiate between sperm that contain a X or Y chromosomes.

Why?

In the agricultural sector sex-selection is most beneficial in industries in which production traits are sex-linked.

For example a dairy farmer may want more female calves to produce milk.

But there are many other reasons why sex may be pre-determined for example:

1) Social: In zoos to maintain normal social structure (usually one male many females)

2) Medical: To prevent sex-linked diseases of humans such as haemophilia.

3) Ecological: Increasing numbers of threatened species

Now this is a nice social

experience!!!!

The problem

Sperm are damaged by sex-sorting and

freezing....

reducing their ability to complete

their mission – to fertilise the egg.

Image: www.kcl.ac.uk

My PhD studies

To explore ways to

protect sperm during

processing for freezing and

sex-sorting

Target animal = sheep

Introduction

• We predicted the fluid, termed seminal plasma, in which the sperm are suspended in upon ejaculation may be the answer to protecting sperm during freezing and sorting.

• We already know that seminal plasma contains proteins that can protect the sperm from certain types of stress.

• So, we reasoned that that we could add these proteins to the sperm and protect them from damage at both the sexing and freezing stages.

Results

We found:

• stressors of sex-sorting cause ram sperm to become more susceptible to reactive oxygen species (oxidative stress)

• Preliminary results suggest this may be due to mechanical insult during processing for sex-sorting

• Addition of seminal plasma proteins or antioxidants (catalase) protects sperm from oxidative damage

Summary

We have had some success and improved fertility but nothing is ever simple and we have identified that:

• The response is variable • It depends on:

• The season of the year seminal plasma is collected .

• At what part of the process the proteins are added.

• How you add the proteins.

So that’s why I choose sex. There is still a lot of work to be done and there is certainly room in our team if

you want to be part of the excitement?

Photo: Tamara 25 years, friendly cow in Spain

We need you on our team In many cases, Australia’s competitors are also placing considerable effort in developing biotechnology

applications for agriculture. Australia is considered generally to be ahead of competitors in the use of genetic markers and artificial insemination for breeding, and is on par with competitors in the use of DNA-based and protein-based diagnostic tests and disease treatments. However, Australia’s agricultural competitors are well ahead in many other areas, including:

• some genome sequencing projects involving Australian species, e.g. Eucalyptus spp;

• proteomics for agriculture (Australia being on par regarding proteomics for human health);

• development of new vaccines (e.g. sub-unit vaccines) for livestock applications;

• biofuels;

• functional foods and nutraceuticals (based on waste products from agriculture); and

• use of biotechnology in the fibre industry.

Further, competitors that have been considered behind Australia in the past, including Brazil and China, are catching up fast. Australia needs to ensure that efforts continue to be applied to developing biotechnology applications where domestic challenges are presented (e.g. high boron soils, salinity, drought, region specific disease strains, and insecurity).

Australia also needs to ensure it captures international developments which are relevant to Australian agriculture (e.g. vaccines and diagnostic tests for diseases which are common elsewhere).

Read all about Biotechnology in Australia here:www.daff.gov.au/__data/assets/pdf_file/0003/437601/non-gm-report.pdf

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BRONZE

Gerringong

& Albion Park

Vet Clinic

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This is a Tamara Leahy presentation

for the 2009