Secrets of chemoreception regeneration of the harderian gland
Download
1 / 28

SECRETS OF CHEMORECEPTION: REGENERATION OF THE HARDERIAN GLAND - PowerPoint PPT Presentation


  • 151 Views
  • Uploaded on

SECRETS OF CHEMORECEPTION: REGENERATION OF THE HARDERIAN GLAND. KING YABUT DR. ROBERT T. MASON DEPARTMENT OF ZOOLOGY OREGON STATE UNIVERSITY. The Harderian Gland. Discovered by Johann Jacob Harder in 1694 Found in virtually all land vertebrates Function remains largely unknown.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'SECRETS OF CHEMORECEPTION: REGENERATION OF THE HARDERIAN GLAND' - Lucy


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Secrets of chemoreception regeneration of the harderian gland

SECRETS OF CHEMORECEPTION: REGENERATION OF THE HARDERIAN GLAND

KING YABUT

DR. ROBERT T. MASON

DEPARTMENT OF ZOOLOGY

OREGON STATE UNIVERSITY


The harderian gland
The GLANDHarderian Gland

  • Discovered by Johann Jacob Harder in 1694

  • Found in virtually all land vertebrates

  • Function remains largely unknown


The harderian gland1
The GLANDHarderian Gland

  • Critical role in garter snake chemoreception

  • Regeneration ability


Thamnophis sirtalis parietalis life history
Thamnophis GLANDsirtalisparietalisLife History

Warm summer months – feeding

Early fall – prepare for winter hibernation

Early spring – breeding


The vomeronasal system and the role of semiochemicals
The GLANDVomeronasal System and the Role of Semiochemicals

  • Chemoreception is crucial to garter snake behavior

  • The VN system is used for detection of non-volatile semiochemicals

    • Female attractiveness sex pheromone

    • Prey chemoattractants – earthworm shock secretion protein

NC=nasal cavity

VNO=vomeronasal organ

HG=Harderian gland

LC=lacrimal canal

LD=lacrimal duct


The role of the harderian gland
The Role of the GLANDHarderian Gland

  • Female attractiveness sex pheromone is a lipid

  • VNO environment is aqueous

  • Harderian Gland is the major source of fluid for the VNO

    • Dyes injected into the HG suggest link to VN system

NC=nasal cavity

VNO=vomeronasal organ

HG=Harderian gland

LC=lacrimal canal

LD=lacrimal duct


The role of the harderian gland1
The Role of the GLANDHarderian Gland

  • Lipid binding proteins from Harderian Gland

    • Homogenate of HG solubilized sexual attractiveness pheromone

    • Harderianectomized males do not court females


Previous research from mason lab
PREVIOUS RESEARCH FROM MASON LAB GLAND

  • HDX snakes also show a loss in feeding behaviors

  • Chemosensory ability began to progressively return indicating a crucial role in feeding behavior


Previous research from mason lab1
PREVIOUS RESEARCH FROM MASON LAB GLAND

  • Study links HG to feeding behavior

  • Previously unknown regeneration ability indicates importance

  • Earthworm prey chemoattractant mechanism still unknown

http://www.crestock.com/image/476113-human-liver.aspx


My research
MY RESEARCH GLAND

Question: Does a relationship exist between the rate of Harderian Gland regeneration and chemosensory recovery in red-sided garter snakes?


My research1
My Research GLAND

  • Hypotheis: The Harderian Gland plays a critical role in chemoreception of red-sided garter snakes and regeneration is correlated to chemosensory ability.


Experimental design
EXPERIMENTAL DESIGN GLAND

  • Purpose

    • Establish a deficit in chemosensory ability using behavioral and biochemical assays

    • Track HG regeneration through time using histology

  • Treatments

    • HDX

    • SHAM


Experimental design1
EXPERIMENTAL DESIGN GLAND

  • Two Protocols to establish deficit

    • Latency to attack – behavioral assay

    • Protein determination – biochemical assay

Photo by Don Powers


Latency to attack protocol
LATENCY TO ATTACK PROTOCOL GLAND

  • Collect earthworm shock secretion for swab


Latency to attack protocol1
Latency to Attack Protocol GLAND

  • Present swab to acclimated snake


Latency to attack protocol2
Latency to Attack Protocol GLAND

  • Time from first tongue flick until bite or to a max of 30 seconds (indicates no bite)


Results swab trial week 1
RESULTS: SWAB TRIAL WEEK 1 GLAND

Significant difference in

bite times (P = 0.025)


Results swab trail week 2
RESULTS: SWAB TRAIL WEEK 2 GLAND

  • Non-biting SHAMs can be

    attributed to other factors

  • Recovered chemosensory

    ability of HDX?


Results swab trial week 3
RESULTS: SWAB TRIAL WEEK 3 GLAND

  • SHAM behavior fluctuates

  • Consistent HDX non-biters

    indicate deficit


Results swab trial week 5
RESULTS: SWAB TRIAL WEEK 5 GLAND

  • Treatment numbers drop

    due to perfusions

  • Consistent non-biters

    remain



Perfusions histology
PERFUSIONS/HISTOLOGY GLAND

  • Perfusion performed weekly to preserve Harderian gland tissue for histology


Protein determination
Protein Determination GLAND

  • Quantify a difference in protein concentration of HG secretions between HDX and SHAM treatment groups


Hg secretion collection

Collect HG secretions GLAND

Pilocarpine

Use secretion

collections to createdilutions with an

unknown amount of

protein

HG Secretion Collection


Protein determination1
Protein Determination GLAND

  • Compare unknown dilutions to a standard curve of known protein concentrations to determine unknown concentrations



Conclusion
CONCLUSION GLAND

  • Behavioral assay

    • Inconsistency in SHAM behavior may be due to other factors

    • Consistent HDX non-biters may indicate a deficit in chemosensory ability

    • Results are incomplete until correlated with histology

  • Protein determination

    • Significant statistical difference between SHAM and HDX protein concentrations (P = 0.027)


Acknowledgements
ACKNOWLEDGEMENTS GLAND

Dr. Robert T. Mason

Dr. Kevin Ahern and the Howard Hughes Medical Institute

Chris Friesen

Rocky Parker

Mason Lab –Ben Burke, Miranda Babcock-Krenk, Mattie Squire, Kata Haeberlin


ad