Types of pheromone in the mammals and Their functions

Mammalian pheromones, including those of humans, occur in four varieties, primer, releaser, signaler, and modulator, which, respectively, affect endocrine responses, elicit behavior, provide information, and influence emotion.Pheromones assist in reproduction, feeding, social interactions and maternal-neonatal bonding in mammals. By definition and according to evolutionary theory, pheromones work within a species. Some chemicals operate between species

1. University of Chakwal, Pakistan

2. Topic: Types of Pheromones in Mammals and
their Functions
Department of Zoology
Presented by: Hina Mubashar
Roll no# UOC-BSZOL-F2020/020
BS Zoology
Session: 2020-2024
Course Title: Endocrinology
Instructor Name: Dr. SyedaNadia Ahmad

3. Introductoion
❑Introduction
❑Chemical nature
❑Types
❑Production
❑Detection
❑Functions

4. Introduction
▪Allanimalshavetocoordinatetheiractivitywithothermembersof
theirspecies.Thisrequiressomeformofcommunication,which
involvestheuseofchemicalsignals,knownaspheromones.
▪KarlsonandLuscher(1959)initiallyproposedtheterm
pheromones.
▪Theydefinedpheromonesas“substancessecretedtotheoutsideof
anindividualandreceivedbyasecondindividualofthesame
speciesinwhichtheyreleaseaspecificreaction,forexample,a
definitebehaviorordevelopmentalprocess.”
▪Thetermpheromoneisusuallyreservedforchemicalsignalsthat
areproducedandreceivedbymembersofthesamespecies,in
whichboththesenderandreceiverofthesignalgainbenefit(Wyatt
2003).

5. Chemical Nature of Pheromones
Organiccompounds:
Pheromonesareorganiccompoundsmadeupofcarbon,hydrogenandoxygen.
Theyaresmallandsimpleinstructure.
Structuralspecificity:
Theirchemicalstructurevariesgreatlyamongspecies.Forexampleinsects
pheromonescanbecomposedofhydrocarbons,whereas,mammalian
pheromonesmightincludesteroidsoraminoacidsderivatives.
Sizeandpolarity:
Importantfeaturesofchemicalsusedaspheromonalsignalsaretheirsizeand
polarity,whichdeterminetheirvolatilityinairandsolubilityinwater.
Volatility:
Pheromonesarevolatile,allowingthemtodispersethroughairandtransmit
signalsoverdistances.Thisvolatilityisessentialforlongrangecommunication
withinaspecies(Carde,R.T.,&Haynes,K.F.2004)

6. Pheromones Production
Animalsusedifferentmechanismsforreleasingpheromonesinto
theenvironment.
Inmanycases,pheromonalreleaseuseexistingroutesfor
excretion,suchasurineandfeces.Forinstance,theurinemarks
usedbyrodents.
Otherroutesofpheromonereleaseinvolvebiologicalsecretions.
Hamstersreleasethesexualattractantprotein,aphrodisin,intheir
vaginalsecretions.
Mostspeciesofcarnivorehaveanalglands,whichproduce
pheromones.

7. Pheromones Production
Therabbitmammarypheromoneis
producedbyglandsaroundthenipplesand
ispresentinrabbitmilk.
Severalpotentialchemosignalshavebeen
identifiedinthesalivaofdifferentspecies.
Otherspecializedscentglandsinclude
chinglands,interdigitalglandsandsternal
glands.(Brennan,P.A.2010).
https://assignmentpoint.com/wpc
ontent/uploads/2017/06/Pheromo
ne-0.jpg

8. Releaser
Pheromones
Primer
Pheromones
Signaler
Pheromones
Modulator
Pheromones
Pheromones
Types

9. Types of Pheromones
1.Releaserpheromones:
Theseelicitanimmediateresponse
theresponseisrapidandreliable.
Theyareusuallylinkedtosexualattraction.
2.Signalerpheromones:
Theseprovideinformation.
Theymayhelpthemothertorecognizehernewbornbyscent.
Signalerpheromonesgiveoutourgeneticodorprint.

10. Types of Pheromones
3.Primerpheromones:
Thesetakelongertogetaresponse.
Theycaninfluencethedevelopmentorreproductionphysiology,
includingmenstrualcyclesinfemales,puberty,andthesuccessor
failureofpregnancy.
Insomemammals,scientistsfoundthatfemaleswhohadbecome
pregnantandwereexposedtoprimerpheromonesfromanother
malecouldspontaneouslyabortthefetus.

11. Types of Pheromones
4.Modulatorpheromones:
Theycaneitheralterorsynchronizebodilyfunctions.
Theyareusuallyfoundinsweat.
Inanimalexperiments,scientistsfoundthatwhenplacedon
theupperlipoffemales,theybecamelesstenseandmore
relaxed.
Modulatorhormonesmayalsoaffectafemale’smonthly
cycle.
(http://www.medicalnewstoday.com/articles/232635)

12. Mammalian Pheromones
Proboscidea
AsianandAfricanelephantsinvestigatedfortheir
pheromonalresponsesbythelateBetsRasmussen.
Duringmusth,elephantsproducelargequantitiesofa
specificpheromone,frontalin,thatisreleasedin
temporalglandsecretions,urine,andbreath.
Adultmalesaremostlyindifferenttofrontalin,
whereassubadultmalesarehighlyreactive.
Femalechemosensoryresponsestofrontalinvarywith
thehormonalstatus.
FemaleAsianelephantsexcreteaurinarypheromone,
tosignaltomalestheirreadinesstomate.
Figure: Musth condition
https://brill.com/view/journals/b
eh/159/3-4/article-p207_1.xml

13. Marsupialia
Inmarsupials,thegrayshort-tailed
opossum(Monodelphisdomestica)
communicatesbyscentmarking.
Themaleopossumpossessesa
prominentsuprasternalscentgland,
whoseextractsstronglyattract
femaleopossums
Stimulatingtheestrusinanestrous
femalesviathevomeronasalsystem.
Figure: Grey short-tailed opossum
https://www.researchgate.net/figure/The-
Grey-Short-tailed-Opossum-
Monodelphis-domestica-A-Opossum-
pups-at-P7-attached-to_fig12_51786664

14. Primata
Primatesrelyonchemicalcommunication
Thering-tailedlemur(Lemurcatta)exhibits
thehighlydevelopedolfactorysystem.
Lemurcattapossessesscentglandsanda
varietyofscent-markingdisplays.
Bothsexeshaveapocrine,locatedonthe
wrists,andsebaceousglandfieldsintheir
genitalregions.
Malesmixtheglandularsecretionsandthen
depositthismixturevia“wristmarking.”
Figure: Ring-tailed lemur
https://lemur.duke.edu/discover/
meet-the-lemurs/ring-tailed-
lemur/

15. Soricomorpha(Insectivores)
Intreeshrew(Tupaiabelangeri),
Bothmalesandfemalesmarktheir
surroundingswithurineandskin
glandsecretions.
Malesmarkmorefrequentlythan
females.
Malescentstimulatesmarkingin
females.
Interestingly,increasingamountsof
malescentresultinacorresponding
increaseinmarkingbyfemales.
Figure: Tree shrew
https://www.pinterest.com/pin/co
mmon-treeshrew-tupaia-glis--
416231190537645906/

16. CarnivoraandUngulata
Bothcarnivores(dogsandcats)andungulates
commonlymarktheirterritorywithurineand
displayaspecificbehaviorcalled“flehmen”.
Intheflehmenreaction,animals,afterthephysical
contact,liftthehead,drawbacktheirlips,and
pushthetonguetowardstheanteriorregionofthe
palate.
Thisattitudewouldallowafastertransferof
pheromonesintotheolfactoryorgans.
Thesalivaoftheadultmalepigcontainsamixture
ofsteroids(boarodor).
Whenaboarbecomesaggressiveorsexually
aroused,itproducescopiousamountofsaliva
whosepungentodorisattractivetoestrusfemales.
Themajorcomponentoftheboarodoris
androstenone(Tirindelli,et.al,).
Figure: Flehmen reaction
https://www.boarbetter.com/en/t
he-importance-of-odour/

17. Pheromones in Humans
Pheromonesinhumansmaybepresentinbodilysecretionssuchas
urine,semenorvaginalsecretions,breastmilkandpotentiallyalso
salivaandbreath.
Yetmostattentionthusfarhasbeendirectedtowardaxillarysweat.
Theaxillarysecretionsoriginatefromthehighlydenseeccrineand
apocrine(whichsecreteintohairfollicles)sweatglandsand
sebaceousglands.
Thesecretionsareodorlessbutapocrinesweatacquiresodorafter
interactionwiththecutaneousbacterialmicroflora.

18. Pheromones in Humans
Odordispersalismodulatedbyseveralfactorsincluding
Clothinglayers
Axillarytemperature
Totalhairsurface
Armmovements
Themaincomponentsofsweatare
Simpleorganicacids(eg,e-3-methyl-2-hexenoicacidand
3-methyl3-hydroxylhexanoicacid)(Hays,2003).

19. Chemosensory Systems Detecting Pheromones
•responsible for recognizing
conventional volatile
odorant molecules
Olfactory
system
•used for sensing
pheromones
Vomeronasal
system

20. VomeronasalEpithelium
Thevomeronasalepitheliumispartofthe
vomeronasalorgan(VNO)ofJacobson.
Atubularstructureencasedinaprotectivebony
capsule
Locatedatthebaseofthenasalseptum.
Thevomeronasalepitheliumcannotbereached
bytheairstreamthatregularlyflowsthroughthe
nasalcavity.
Bloodvesselsandsinusesinducesvasodilation
andvasoconstriction,producingapumplike
actionforstimulusaccesstothelumen.
Figure: Sensory system
https://tiesalesm.live/produ
ct_details/27246876.html

21. VomeronasalEpithelium
Inungulates,the“flehmen”behavioristhoughttobeassociatedwith
promotingstimulusaccesstothevomeronasalorgan.
Inthemouse,thevomeronasalsensoryepitheliumincreasesfrombirth
topubertyandbecomescompletelyactiveat2monthsafterbirth.
Dohumanhaveavomeronasalorgan?
Vomeronasalorganispresentinhumanembryos,containbipolar
neurons.
Thevomeronasalstructurebecomesmoresimplifiedlaterin
development.
Severalreportsshowedthatinhumanadultsitbecomesablind-ended
diverticulumintheseptalmucosa.

22. Olfactory Epithelium
Theolfactoryepitheliumisthelargestolfactorystructureinmice,
containingmillionsofsensoryneurons
detectairborneodorantsandpheromonesthatenterthenasalcavity
throughthenostrils.
detectingodorantsatspecializedciliathatcontaintherequisitereceptors
andsignalingcomponents.
Olfactorysensoryneuronsenterthebrain,wheretheyformsynaptic
connectionsintheolfactorybulb.
Thearchitectureoftheolfactoryepitheliumisparticularlyconducivefor
detectingvolatileodors.

23. Olfactory Epithelium
Inmouse,theolfactorysystemisfunctionally
establishedduringtheprenatalphase.
Thefirstaxonscontactthetelencephalicvesicle
aroundembryonicday13.
Conversely,axonaltargetingtospecificdomains
withinthemainolfactorybulboccursasearlyas
embryonicday15.5. Figure: Olfactory Epithelium
https://www.sciencedirect.com/science/arti
cle/pii/S0896627305003922

24. Functions
Pheromonesacrossdifferentspeciesperformcertain
functionsthatactsastriggersorcuestoresponses
fromothermembersofthesamespecies:
Sexualarousaltrigger
Raisingthealarm
Warningsystem
Territorymarking
Bondinghormone
Foodtrialmarker
Usetocommunicate
Recognitionbetweenmotherandoffspring
Figure: Bonding hormones
https://www.123rf.com/photo_6281955
0_smiling-mother-and-father-holding-
their-newborn-baby-daughter-at-
home.html

25. References
Brennan,P.A.(2010).Pheromonesandmammalianbehavior.The
neurobiologyofolfaction.
Liberles,S.D.(2014).Mammalianpheromones.Annualreviewof
physiology.
Zufall,F.,&Leinders-Zufall,T.(2007).Mammalianpheromone
sensing.Currentopinioninneurobiology.
Tirindelli,R.,Dibattista,M.,Pifferi,S.,&Menini,A.(2009).From
pheromonestobehavior.Physiologicalreviews.
HaysWST.Humanpheromones:havetheybeendemonstrated?
BehavEcolSociobiol2003.