Who ar e t he My t i l us t r os s ul us ? • Th e M. t r o s s u l u s a r e c o mmo n ma r i n e mu s s e l s • Fo u n d a l o n g r o c k y s h o r e l i n e s o f No r t h Ame r i c a i n t h e i n t e r t i d a l z o n e a n d s p a n f r o m h i g h t i d a l z o n e t o l o we s t t i da l poi nt . • Co l o n i z e i n c l u mp s o n r o c k s • Ar e a f o u n d a t i o n s p e c i e s - a d o mi n a n t s pe c i e s i n a ha bi t a t t ha t a r e a bunda nt a nd ha ve ma j o r i n f l u e n c e o n t h e e c o s y s t e m • Ar e a l s o I n d i c a t o r s p e c i e s – a s t he y r e pr e s e nt t he ove r a l l he a l t h of a n e c os ys t e m a nd a r e i n f l u e n c e d b y e n v i r o n me n t a l c o n d i t i o n s : Who ar e t he My t i l us t r os s ul us Ph y l u m Mo l l u s c a Cl a s s Bi v a l v i a Su b c l a s s Pt e r i o mo r p h i a Or d e r My t i l o i d a Fa mi l y My t i l i d a e Ge n u s My t i l u s Sp e c i e s t r o s s u l u s Mus s el s : An i deal model t o s t udy oxygen met abol i sm • Re s i d e i n i n t e r t i d a l z o n e – s ubj e c t e d da i l y t o e xt r e me f l uc t ua t i ons i n oxyge n l e ve l s • Se s s i l e o r g a n i s ms - eas i er t o mi ni mi z e s t r e s s on a ni ma l s r e s ul t i ng f r om c a pt i vi t y a nd t e s t i ng pr oc e dur e s . No move me nt = no i nt e r f e r e nc e wi t h e qui pme nt • Mu s s e l s c a n l i v e f o r e x t r e me l y l ong pe r i ods i n t he pr e s e nc e of a noxi a ( no oxyge n) . – o Mussel s: Over comi ng adver si t y • Mu s s e l s a r e we l l a d a p t e d t o t h e p r o b l e ms f a c e i n l o w a n d h i g h t i de s : – Fi l t e r f e e d i n g o r g a n i s ms t ha t us e de l i c a t e g i l l s t o t r a p n ut r i e nt s i nc l udi ng oxyge n – I n t h e s u b me r g e d s t a t e , oxyge n mu s t b e d i s s o l v e d i n wa t e r i n or d e r t o b e t a k e n u p b y gi l l s – Lo w t i d e mu s s e l s wi l l c l a m up a nd e mp l o y s t r a t e g i e s t o s u r vi ve Ov er c omi ng Chal l enges i n Oxygen Fl uct uat i ons • Lo w t i d e p o s e s s p e c i a l p r o b l e ms f o r o r g a n i s ms . • Gi l l r e s p i r i n g a n i ma l s h a v e di f f i c ul t y e xt r a c t i ng oxyge n f r om ai r • Fo r t h o s e l u c k y e n o u g h t o h a v e wa t e r , t i d a l p o o l s a r e wa r me r – oxyge n s a t ur a t i on i n l o we r , c a r b o n d i o x i d e r e a di l y i nt o t he pool e s c a pe s i t . - c o - i n h a b i t a n t s c o mp e t wa t e r i s mu c h di s s ol ve s a nd oxyge n e f or a va i l a bl e How do Mussel go wi t hout ? How do t hey sur vi ve t he dr y spel l ? Wi t h l e s s o x y g e n, t he r e c ome s a poi nt whe r e t h e c o s t o f r e s pi r a t i on e xc e e ds t he b e n e f i t o f e x t r a c t i ng oxyge n. Th e t ur n i n g p o i nt i s c a l l e d t he Pc r i t – t he c r i t i c a l o x y ge n pr e s s ur e Th e Pc r i t r e p r e s e nt s t he poi nt whe r e e n v i r o me n t a l oxyge n i s t oo l ow f or a n o r g a n i s m t o ma i nt a i n c ur r e nt oxyge n me t a b o l i s m Wh e n f a c e d wi t h oxyge n s hor t a ge , a n or ga ni s m ha s a c hoi c e : - To o b t a i n e ne r gy f r om ot he r s our c e s - To d e p r e s s me t a bol i s m - To d o b o t h of t he a bove I nvest i gat i ng Hypoxi a Tol er ance • Th e p u r p o s e o f t h i s e x p e r i me n t i s t o f u r t h e r k n o wl e d g e a b o u t t h e me c h a n i s ms mu s s e l s u s e t o s ur vi ve hypoxi c c ondi t i ons NORMOXI A= n o r ma l o x y g e n l e ve l s HYPOXI A = l o we r t h a n n o r ma l oxyge n l e ve l s ANOXI A = n o o x y g e n p r e s e n t Met hods • 3 5 mu s s e l s we r e h a r v e s t e d i n Oc t o b e r 1 5 t h , 2 0 0 7 t o a s s e s s t h e Pc r i t f r o m mi d - t i d a l z o n e s a t Lo c a r n o Be a c h • 4 0 we r e c o l l e c t e d Fe b 1 s t , 2 0 0 8 f o r t h e s e c o n d p h a s e o f t h e e x p e r i me n t • Mu s s e l i d e n t i f i e d b a s e d o n p r e v i o u s mo l e c u l a r g e n e t i c s t u d y o f p 5 3 g e n e ( Mu t t r a y a n d Co x , 2 0 0 5 ) Met hods c ont i nued • Mu s s e l s we r e t r a n s p o r t e d b a c k t o t h e Ri c h a r d s La b a t UBC: – Ba r n a c l e s r e mo v e d a n d s h e l l s c l e a ne d f r om de br i s – Pl a c e d i n a l a r g e a q u a r i um a nd a l l o we d t o a c c l i ma t e f o r a mont h a t 1 2 o C a n d 3 0 p p t s a l i n i t y. – 15 mu s s e l s f r o m t h e f i r s t ba t c h us e d t o t e s t s e t u p a n d 1 6 we r e us e d t o a s s e s s t h e Pc r i t . Met hods c ont i nued • Mu s s e l s we r e t r a n s p o r t e d b a c k t o t h e Ri c h a r d s La b a t UBC: – Ba r n a c l e s r e mo v e d a n d s h e l l s c l e a ne d f r om de br i s – Pl a c e d i n a l a r g e a q u a r i um a nd a l l o we d t o a c c l i ma t e f o r a mont h a t 1 2 o C a n d 3 0 p p t s a l i n i t y. – 15 mu s s e l s f r o m t h e f i r s t ba t c h us e d t o t e s t s e t u p a n d 1 6 we r e us e d t o a s s e s s t h e Pc r i t . Meas ur i ng Ox y gen Cons umpt i on • Mu s s e l s we r e p l a c e d i n r e s p i r o me t e r a n d a l l o we d a 2 4 h r e c o v e r y t o d e s t r e s s pr i or t o c ol l e c t i ng da t a • Re s p i r o me t e r wa s c o n n e c t e d t o a Fo x y Pr o b e – t r a n s mi t s b l u e LED l i g h t a t ~4 7 0 n m a n d q u e n c h i n g o f s i g n a l i s r e a d b y a s p e c t r o me t e r , USB2 0 0 0 - FL Fl u o r e s c e n c e Sp e c t r o me t e r , • Us i n g OOI Se n s o r s So f t wa r e o x y g e n c o n s u mp t i o n wa s a s s e s s e d u s i n g t h e St e r n - Vo l me r e q u a t i o n . • Mu s s e l s we r e a l l o we d a 2 4 h r e c o v e r y t o de - s t r e s s pr i or t o c ol l e c t i ng da t a Appar at us Set up Resul t s on Oxygen Consumpt i on Time Chart Water PO2 (torr) 140.00 120.00 100.00 80.00 60.00 40.00 20.00 0.00 0.00 50.00 100.00 150.00 200.00 250.00 300.00 Time (min) • 16 mu s s e l s we r e t e s t e d a l l o we d t o c o n s u me t h e l t he y c e a s e d t o r e s p i r e • The a b o v e g r a p h s h o ws t a mus s e l i s p l a c e d i n a •For r e f e r e n c e , 1 2 5 t o r r i n a c l o s e d r e s pi r ome t e r a nd i mi t e d a v a i l a b l e oxyge n unt i l h e c o n s u mp t i o n of oxyge n whe n s e a l e d r e s p i r o me t e r . ~ 1 6 % O2 , wh i c h i s t he a mount Conv er t i ng Oxygen Consumpt i on Rat e t o cal cul at e Pcr i t Time Chart 0.02 0.01 umol/g/hr MO2 0.01 0.01 0.01 0.01 0.00 0.00 0.00 0.00 20.00 40.00 60.00 80.00 100.00 120.00 Water PO2 (torr) • The a bove gr a p h s h o ws t h e mo l e c u l a r o x y g e n c ons umpt i on r a t e c a l c u l a t e d f r o m t h e p r e v i o u s s l i de . • Cons umpt i on of Mo l e c u l a r Ox y g e n Co n s u mp t i o n Ra t e r e l a t i ve t o Ox y g e n Pr e s s u r e y i e l d s t h e Pc r i t us i ng r e g r e s s i o n l i n e s . Conv er t i ng Oxygen Consumpt i on Rat e t o cal cul at e Pcr i t • Us i n g r e g r e s s i o n l i n e s t o d e t e r mi n e t h e c o n s u mp t i o n o f Mo l e c u l a r Ox y g e n Co n s u mp t i o n Ra t e r e l a t i v e t o o x y g e n pr e s s ur e . Res ul t s of Pc r i t As s es s ment s • Pc r i t i s t h e t h r e s h o l d p r e s s u r e o f o x y g e n i n wh i c h t h e mu s s e l c a n n o t s u s t a i n u s u a l me t a b o l i c c o n s u mp t i o n r a t e o f o x y g e n • Fr o m d a t a r e s u l t s , i t wa s a s s e s s e d t h a t t h e mu s s e l s h a d a me a n c r i t i c a l o x y g e n t e n s i o n o f 20. 94± 2. 09 t or r ~ 2. 7% a t mo s p h e r i c o x y g e n What does t hi s mean? What happens af t er Pcr i t Phase I I of Mussel Hypoxi a St udy • No w t h a t we h a v e d a t a o n t h e t r a ns i t i on poi nt i n t he oxyge n me t a b o l i s m a n d we k n o w wh a t t h e i r t hr e s hol d i s . • Ve r y l i t t l e i s k n o wn a b o u t t h e e me r g e n c y me c h a n i s ms t h a t mu s s e l s e mp l o y wh e n f a c e d wi t h a n o x y g e n cr i s es • St u d i e s h a v e f o c u s e d o n l o n g t e r m e f f e c t wh i c h s h o w t h a t Mu s s e l s wi l l r e d u c e me t a b o l i c a c t i v i t y – r e q u i r i n g f e we r r e s o u r c e s a n d pr oduc i ng l e s s t oxi c bypr oduc t s The Emer genc y Res pons e • Th e s e c o n d p o r t i o n i s t o a s s e s s me t a b o l i c ma r k e r s me a s u r e ATP, Ph o s p h o a r g i n i n e , Oc t o p i n e ( t h e i nve r t e br a t e e qui va l e nt of l a c t a t e ) . • Th i s wi l l s h o w wh e t h e r t h e mu s s e l ’ s p r i ma r y s u r v i v a l me c h a n i s m i s t o i mme d i a t e l y l o we r me t a b o l i s m o r s wi t c h t o a l t e r n a t e p a t h wa y s t o g e t t h e i r e ne r gy • Fo r e x a mp l e , i f ATP l e v e l s a r e t h e s a me b e f o r e a n d a f t e r Pc r i t , t h e mu s c l e h a s n o t l o we r e d me t a b o l i c The Emer genc y Res pons e • At t h i s p o i n t 4 0 mu s s e l s h a v e b e e n a c c l i ma t i n g : – 1 0 wi l l be us e d a t nor moxi a - c o n t r o l – 1 0 wi l l be s ubj e c t e d a t 20 t or r – 1 0 wi l l be s ubj e c t e d t o 12 t or r ( 2 s t a nda r d de v i a t i o n s b e l o w me a n ) – 1 0 s ubj e c t e d t o c ompl e t e a noxi a • St u d y i s o n g o i n g t o a c q u i r e d a t a t o d e t e r mi n e ATP, Ph o s p h o a r g i n i n e , Oc t o p i n e i n Mu s s e l Ti s s u e s • Da t a wi l l a l l o w f u r t h e r o r u n d e r s t a n d i n g i n t o h o w t h e My t i l u s t r o s s u l u s ’ s u s e s e me r g e n c y me t a b o l i c c o p i n g me c h a n i s ms t o h y p o x i a s t r e s s e s Ac k nowl edgment • I wo u l d l i k e t o t h a n k a udi e nc e f or t he i r a t t • Th e Ri c h a r d s La b s f o r t he i r f a c i l i t i e s • Dr . J e f f Ri c h a r d s Ph D pa t i e nc e a nd gui da nc e . t he e nt i on us e of f or hi s I ma ge s of mu s s e l s a r e a l t e r e d p i c t u r e s . Or i g i n a l s we r e o b t a i ne d f r om t he i nde x f ound on ht t p: / / www. wa l l a wa l l a . e du / a c a d e mi c s / d e p a r t me n t s / b i o l o g y / r os a r i o/ i nve r t s . D. Cowl e s ( 2 0 0 2 ) I ma ge f or OOSe n s o r Fo x y p r o b e c a n b e f o u n d a t :
- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Undergraduate Research /
- Assessing hypoxia tolerance in the Mytilus trossulus
Open Collections
UBC Undergraduate Research
Assessing hypoxia tolerance in the Mytilus trossulus Mader, Heidi Mar 8, 2008
Page Metadata
Item Metadata
Title | Assessing hypoxia tolerance in the Mytilus trossulus |
Creator |
Mader, Heidi |
Date Issued | 2008-03-08 |
Description | Presented at the Multidisciplinary Undergraduate Research Conference on March 8, 2008 in the Irving K. Barber Learning Centre, University of British Columbia. Abstract: Organisms that reside in the intertidal zone are routinely subjected to extreme fluctuations of oxygen levels. To cope with subnormal available oxygen in an environment, organisms must either reduce their metabolic activity, switch to alternate biochemical pathways to generate cellular energy, or use a combination of the two. Using the marine mussel, Mytilus trossulus, in a two-part investigation, the critical oxygen tension (Pcrit) was assessed to determine the point at which the animal could no longer maintain normal metabolic activity. With this information, the metabolic responses were analyzed for the second part of the experiment to gain further insight into how alternate biochemical pathways aid the mussel to overcome prolonged oxygen deprivation. |
Extent | 8728576 bytes |
Genre |
Presentation |
Type |
Text |
FileFormat | application/vnd.ms-powerpoint |
Language | eng |
Series | University of British Columbia. Multidisciplinary Undergraduate Research Conference |
Date Available | 2008-08-05 |
Provider | Vancouver : University of British Columbia Library |
Rights | Attribution-NonCommercial-NoDerivatives 4.0 International |
IsShownAt | 10.14288/1.0081273 |
URI | http://hdl.handle.net/2429/1266 |
Affiliation |
Science, Faculty of |
Peer Review Status | Unreviewed |
Scholarly Level | Undergraduate |
Copyright Holder | Heidi Mader |
Rights URI | http://creativecommons.org/licenses/by-nc-nd/4.0/ |
AggregatedSourceRepository | DSpace |
Download
- Media
- 42446-heidi_mader_mussel.ppt [ 8.32MB ]
- Metadata
- JSON: 42446-1.0081273.json
- JSON-LD: 42446-1.0081273-ld.json
- RDF/XML (Pretty): 42446-1.0081273-rdf.xml
- RDF/JSON: 42446-1.0081273-rdf.json
- Turtle: 42446-1.0081273-turtle.txt
- N-Triples: 42446-1.0081273-rdf-ntriples.txt
- Original Record: 42446-1.0081273-source.json
- Full Text
- 42446-1.0081273-fulltext.txt
- Citation
- 42446-1.0081273.ris
Full Text
Cite
Citation Scheme:
Usage Statistics
Share
Embed
Customize your widget with the following options, then copy and paste the code below into the HTML
of your page to embed this item in your website.
<div id="ubcOpenCollectionsWidgetDisplay">
<script id="ubcOpenCollectionsWidget"
src="{[{embed.src}]}"
data-item="{[{embed.item}]}"
data-collection="{[{embed.collection}]}"
data-metadata="{[{embed.showMetadata}]}"
data-width="{[{embed.width}]}"
async >
</script>
</div>

http://iiif.library.ubc.ca/presentation/dsp.42446.1-0081273/manifest