LES PHEROMONES
Évocation historique.
« Pheromones,
historical perspectives »
Colloque AROMAGRI 2008
François Clarac,
24 septembre 2008
From insect behaviours
to human vomeronasal organ…
1/ Origins…
2/ Search of a definition.
3/ Some examples of pheromones
4/ electrophysiolocal analysis
AGOSTA, W.C. 1992. Chemical Communication: The Language of Pheremones.
Scientific American Library.
BROSSUT, R. 1997. Phéromones: La communication chimique chez les animaux.
Belin. Paris.
DUPONT J-C.,2002. "Les molécules phéromonales. Éléments d'épistémologie
historique," Philosophia Scientiae, 6, p. 50-59
HAMON, A. (2006), La communication olfactive dans le monde animal
Université d’Angers.
LOUVEAUX, J.,1996. Les Abeilles et l'apiculture: 1940-1981. Inra édition……
I/ ORIGINS…
Studies from Jean-Henri Fabre
(1823-1915)
Living in Serignan at
« Harmas house, fallow Land ».
He wrote his « Souvenirs
Entomologiques ».
The first volume written by Dr. Legros, is the
Fabre’life. In the other 9 volumes, Fabre
described the insect behaviours of the
Comtat Venaissin (Ventoux).
In the volume 7, p. 363-423, he described a
very curious phenomenon.
The giant peacock moth
( Saturnia pyri) Le grand Paon de nuit
Slightly by chance,
Fabre, one morning saw
a female of the giant
peacock, just at birth. He
collected it and kept it in
a box covered by a
metallic cloth
In the evening occured a
fantastic show!!!!


« Ce fut une soirée mémorable. Je l’appellerai la soirée du grand
Paon…une femelle quitte son cocon en ma présence…je la cloître
aussitôt, sous une cloche métallique. Bien m’en prit. Vers les neuf
heures du soir…à demi déshabillé, petit Paul va, vient, court saute,
trépigne, renverse les chaises comme affolé. Je l’entends m’appeler
Viens, clame-t-il; viens voir ces papillons, gros comme des oiseaux!
la chambre en est pleine! »
The role of the antennae
During 8 days, each evening
he observed the same behaviour.

During the 8 evenings, 150 males were
collected…even their few numbers around
Sérignan.…
Fabre tried to define the attractive stimulus..
 He cut the antennae to some males,…
they never came back…



Caterpillar and a cocoon of
the giant peacock moth
Fabre use another
animal and takes a
peacock butterflie that
has its main behaviour
during the day .
He observed the same
reactions that happened
at the hotest moments
of the day.


The emperor moth
« Le minime à bande »

this animal is even quite
rare in the region and it
arrived even more males
that are attracted by the
female.
Fabre was convinced
of an olfactory effect
but
without any odours!!!

Leaving an oak’branch
near a female, taking it
after several hours and
putting it in another part of
the room, he observed
that all the males were
attracted by the branch.
He supposed that an
odour has impregnated it.
He defined then two types
of « olfaction »




Fabre’explanation
He considered two types of olfaction: « En son ensemble, l’olfaction aurait
ainsi deux domaines: Celui des particules dissoutes dans l’air et celui des
ondes éthérées. Le premier seul nous est connu. Il appartient également à
l’insecte. C’est lui qui renseigne le Saprin sur les fétidités du serpentaire, la
Silphe et le nécrophore sur les puanteurs de la taupe.
Le second, bien supérieur en portée dans l’espace nous échappe
complètement, faute d’outillage sensoriel nécessaire. Le grand paon et le
minime le connaissent au moment des fêtes nuptiales. Bien d’autres doivent
y participer à des degrés divers, suivant les exigences de leurs genres de
vie. »
Karl von Frisch ( 1886-1982)
confirmed in 1919 the role of the
antennae in the odour’perception

Albrecht Bethe
(1872-1954),
studying in details
the
insect’behaviours
used the term
« ectohormones »

En 1932, Bethe considered that with the hormones, it exists others
substances that are produced externally
 and that could play a similar role.
 A. Pickens (1932) used another term and spoke
 about a « social-hormone ».
PP. Grassé (1895-1985) supported that explanation.
Substances
in honeybee’colonies: studies
from J. Pain and C.G. Butler

J. Pain worked at Bures sur Yvette
on the relations between
queen/ workers.
 She demonstrated that a « dead
queen » prevent the development of
sexual organs of the workers.

1956: C. Butler works
also on a queen
substance that prevent
the development of the
queen cell. This
pheromone is a « 9-oxo2-décénoïc acid ».
1956:
J. Pain speaks about a
substance produced by the
queen, a «ectohormone ».
II/ Search of a DEFINITION
Karlson and Lüscher
( Nature, 183, p.55-56, 3/1/1959).


The term of pheromone
is derived from two
greec roots:
 Pherein: to transfer
 Hormön: to excite
« Pheromones are defined as
substances which are secreted
to the outside by an individual
and received by a second
individual of the same species,
in which they release a specific
reaction, for example, a definite
behaviour or a developmental
process»
Annual Reviews « Pheromones (ectohormones)
in insects » by P. Karlson et A. Butenandt (1959)

AFJ. Butenandt (1903-1995), was Nobel Price
(1939) in chemistry for the discovery of the
sexual hormones sexuelles ( testostérone).
 With Karlson, interested by insect
metamorphosis, they identified the ecdysone.
In 1959, Butenandt used 500.000 females of the
silkworm moth to characterize a sex pheromone,
the Bombykol. This pheromone released by the
female silkworm moth to attract mates, was the
first pheromone to be characterized chemically.


Stereochemistry of the Bombykol
Discussions about queen substances
with J. Pain, M. Barbier .
Article 1963:
 Considering the behaviour, the authors
proposed that queen and workers produce
various lipid fractions a mixture of
substances:
 Pherormone I ( queen substance,
9-oxo-2-décénoïc acid ): its inhibits the queen-cell
construction.
 Pherormone II: ensemble of substances
(azelaic acid, sebacic acid, phenyl acetic acid…) that
induced:
 -an attractive power around the queen. inhibits the developpement of ovaries in
workers.
 -attraction of the males during the « flight
wedding ».



Edward O. Wilson
wrote in the
«Scientific
American » a review
on the pheromones
from the ants.
A drop of a sugar solution is disposed far from the nest of the
ants: When a worker found the source of food, a pheromone is
laid down. Sometimes the chemical message is reinforced by
the touching of antennae.
Exocrine glandular system of a worker ant:
Some pheromones are stored in « reservoirs »
and released in bursts only when needed;
others are secreted continuously.

Trail substances
are produced
by Dufour’s gland,
Pavan’s gland
or the poison gland.
Alarm substances
are produced by
the anal and
mandibular gland…
III/ Some examples of Pheromones
Pheromones exists in all animal
groups, in the air as in the water.
 Those produced in « air » are
volatile and composed of
small molecules
 In water, they are soluble.


Those associated to a landmark, are
persistent and then are in general
composed of high molecular weight



These substances are
produced in very limited
quantities:
A pheromone is coming
from an exocrine gland
and is secreted in the
external medium.
Narrow specificity and
High Potency
 Chemical components of pheromones are
long chains of carbon saturated or unsaturated
with alcool, aldéhyde, Ketone functions….
A complex classification …

Releaser Pheromones are powerful attractant molecules that
some organisms may use to attract mates from a distance of two miles
or more. This type of pheromone generally elicits a rapid response but
is quickly degraded..

Primer Pheromones trigger a change of developmental events. In
contrast, it has a slower onset and a longer duration..
Mainly in insects, and are considered :
Kairomones: Chemical substance produced and

released by a living organism that benefits
the receiver and disadvantages the donor
( Mosquito attracted by human pheromones..)
Allomones: Interspecific communication with a positive
effect to the originator (the formic acid produced by ants…).

Pheromones: intraspecific communication
Agosta, W.C. 1992. Chemical
Communication:
The Language of Pheremones.
sex pheromones


In animals, sex pheromones indicate
the availability of the female for
breeding. Male animals may also
emit pheromones that convey
information about their species and
genotype.
 It was that sort pheromones that
Fabre has described in the
« Harmas ».
The Golden Hamster, Mesocricetus auratus : Dimethyldisulfide
(DMDS) is present in hamster vaginal secretion and has been
reported to be responsible for the male hamster's attraction.

Trail Pheromones
Active space of ant trail within which the pheromone is
dense enough to be perceived by other workers. The
rapidity with which the trail evaporates is rapid.
Less than two minutes.

(Animal Behaviour, 1962, 10 p.134-167).
 Response of workers in an artificial nest to
evaporated trail substance. Air is being drawn
into the nest. At the start few workers are
foraging outside the nest.
Within a short time after the glass rod has been
dipped into Dufour’s gland concentrate and
replace, a large fraction of workers leaves the
nest and moves in the direction of the rod.


Experiment from Wilson
Alarm Pheromones



Hops can be invaded by greenflies.
They can produced an alarm
pheromone, the bêta-farnésène.
 Plant reacts in inducing its
inhibitor.
The Green lacewings is attracted by
the inhibitor
Alarm pheromone is released
by an animal as an alarm
signal that induces a fear or
fright response in members of
the same species.
In général animals that live in
group produce much more
pheromones, that those living
alone.
Le bêta-farnésène
Territorial Pheromones
Animals in their
environment leave
some substances that
circumscribe their
territory.



A Stag, on heat
In some mammals it is
in the urine. In others it
is due to the contact of
the head with branches.
Secretion is coming
from pre-orbital glands.
Aggregation Pheromones

These pheromones favoured meetings between individuals
The scolyte attacks pine
trees and destroys them in
few days. It attacks weak
trees and the pionnieers
attracted thousand of other
individuals in producing
« frontaline ».
 this pheromone induces
this massive attack.

IV Electrophysiology in antennae
Similarities between insect and mammal
sensory reception.
Mammals
Large, tactile et
gustative sensilla,
Small, olfactive sensilla
M. Lesourd in Masson
et Brossut,
La Recherche
n°121,1981
In the mucus are
« odorant binding protein ( OBP) »
that seemed to be associated with
Pheromone’ molecules.
Insects
Dispositive for an
electrophysiological recording of a
bee or of a wasp’ antenna
(Insecte Sociaux 1956)


Comparison of olfactive
responses between wasps
(A,B,C) and bee (D,E,F) to
lavanda odours.
D. Schneider, Z. vergl. Physiol., 1957
 Electrophysiologische untersuchungen non chemo-und mechanorezeptoren des
Antenne des Seidenspinners Bombyx mori
 J.Boeck, H. Sass & DRA. Wharton, Nature 1970.
Electroantennograms are recorded from the entire antennae of Periplaneta.
 Stimulation is done with specific natural odorous attractant produced by
virgin females

Recording at the level of the
deutocerebrum
Anatomy of the
deutocerebrum of the
bombyx anrthenea
polyphemus.


Staining of neurons with cobalt

( J. Boeck & V. Boeck, J. Comp.
Physiol. 1979)

Response of a pheromone
sensitive neurone to
different substances or
female glands.
CONCLUSION:
Notion of chemical communication
New Ethological Perspectives:
 The chemical communication
can be considered as a slow
phenomenon, the first in the
evolution.

By contrast to the
importance of vision and of
audition in human,
pheromones correspond to
very specific mean of
communication quite useful
in all the different species.



Is-it the animal langage?

Innate and acquired
phenomenon:
Innate for transmitter
acquired for receiver

In Agriculture
pheromones or inhibitory
compounds seemed a
much better way to
destroy different nocive
species, at least much
better than the DDT.
Applied developments
The European Corn Borer (Ostrinia nubilalis)
is a pest of grain, particularly maize
For human, if the presence of
phéromones has been deeply
discussed, their presences has been
the occasion of production of new
commercial products far from science
(aphrodisiac substances…)

These first years have been crucial for
that new concept of « Pheromone »,…
-Identification of genes coding for olfactive receptors
and those for biosynthesis pheromone enzymes
( Nobel Price to Richard Axel and Linda B. Buck in 2004)
.-Neuro-endocrine control of pheromone production: Function of sex
specific neuronal pathways.
-Computational methods with electronic nose
The
vomeronasal’organ
(VNO)discovered in 1813 by the
danish Ludvig Jacobson, is
disposed under the internal part
of the nose and specific in
recording the pheromones.
Drawing from Jacobson
Present
in the most of vertebrates,
 in humans VNO is reduced.
Døving KB, Trotier D (1998).
« Structure and functiono
of the VNO »
FIN
Complexities of the pheromones
Pheromone participates at the different stages of the life
and they interact not only with the medium but also with
the other members of its species and in some circumstances
with other species.

In insect, their relations with
plants exists at two levels:
1) with pollination.
2) when they eat plants.
Often plants produce
substances that can facilitate
or inhibit pheromones
LM Riddiford
( Science, 158,139-140,
1967)
isolated the volatile
compound, the trans-2hexanal from oak leaves
that stimulate the female
polyphemus moth to release
her sex pheromone.

Yamada et al. Nature, 1970,
227, 855:
Odours are recorded at the level of
the olfactory lobe of the cockroach
Periplaneta americana.

Chemistery of pheromones
6 sex pheromones …
From O. Wilson 1963
Considering their
biosynthesis, 3 pathways
are present in insects:
1) The fatty acid pathway:
long chains of carbon
satturated or unsaturated
with alcool, aldéhyde or
Ketone function.
2) The isoprenic pathway:
with the isoprenic unit
(C5H8).
3) The acetogenic pathway:
The pheromones are
synthétised from an
elementary unit of
l’acétone (C3H6O).

Antennography can be linked with
chromatography
When using gas
chromatography linked to
electroantennogramme
recordings from an insect
antenna the column
effluent is split in two,
half of it, is diverted to
the chromatographic
detector and the second
half is blown over the
insect antenna used as a
biological detector.
This combination permits
the isolation of
biologically active
compounds in complex
mixtures of products.